1990 Jaguar XJS - Voltage Drop While Driving.
#21
A bit of reassurance... Is this the crank seal that I will want and need with the damper pully removal? A while I am in there, thing...?
#22
NO NO NO.
The pulley arrangement of teh V12 is made up of:
An 11A Section "V" closest to the engine, and this IS laminated to the central hub, and drives the alternator ONLY.
A "pulley pack" comprising of 3 X 13A V sections. This is bolted by 4 bolts to that central hub, NOTHING to do with the laminated V pulley. These 3 "V" sections drive, water pump and steer pump, a/c and air pump or idler, engine driven fan.
Your a/c and "smog pump" would have been from one of the 3 on the pulley pack.
BUT
Somewhere around 1991ish, Jaguar went to a flat Serpentine (Multi V) belt for the alternator, and this coincided with the introduction of the HIGH Amp alternator fitment from the factory.
As said, I believe your engine has the 4 V style belts, with the closest to the engine being thinner (not so thick) as the other 3.
This parts snap shows what the words are attempting. #13 is the laminated section, and #15 is the pulley pack, simple now.
The pulley arrangement of teh V12 is made up of:
An 11A Section "V" closest to the engine, and this IS laminated to the central hub, and drives the alternator ONLY.
A "pulley pack" comprising of 3 X 13A V sections. This is bolted by 4 bolts to that central hub, NOTHING to do with the laminated V pulley. These 3 "V" sections drive, water pump and steer pump, a/c and air pump or idler, engine driven fan.
Your a/c and "smog pump" would have been from one of the 3 on the pulley pack.
BUT
Somewhere around 1991ish, Jaguar went to a flat Serpentine (Multi V) belt for the alternator, and this coincided with the introduction of the HIGH Amp alternator fitment from the factory.
As said, I believe your engine has the 4 V style belts, with the closest to the engine being thinner (not so thick) as the other 3.
This parts snap shows what the words are attempting. #13 is the laminated section, and #15 is the pulley pack, simple now.
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Dukejag (04-14-2020)
#23
NO NO NO.
The pulley arrangement of teh V12 is made up of:
An 11A Section "V" closest to the engine, and this IS laminated to the central hub, and drives the alternator ONLY.
A "pulley pack" comprising of 3 X 13A V sections. This is bolted by 4 bolts to that central hub, NOTHING to do with the laminated V pulley. These 3 "V" sections drive, water pump and steer pump, a/c and air pump or idler, engine driven fan.
Your a/c and "smog pump" would have been from one of the 3 on the pulley pack.
BUT
Somewhere around 1991ish, Jaguar went to a flat Serpentine (Multi V) belt for the alternator, and this coincided with the introduction of the HIGH Amp alternator fitment from the factory.
As said, I believe your engine has the 4 V style belts, with the closest to the engine being thinner (not so thick) as the other 3.
This parts snap shows what the words are attempting. #13 is the laminated section, and #15 is the pulley pack, simple now.
The pulley arrangement of teh V12 is made up of:
An 11A Section "V" closest to the engine, and this IS laminated to the central hub, and drives the alternator ONLY.
A "pulley pack" comprising of 3 X 13A V sections. This is bolted by 4 bolts to that central hub, NOTHING to do with the laminated V pulley. These 3 "V" sections drive, water pump and steer pump, a/c and air pump or idler, engine driven fan.
Your a/c and "smog pump" would have been from one of the 3 on the pulley pack.
BUT
Somewhere around 1991ish, Jaguar went to a flat Serpentine (Multi V) belt for the alternator, and this coincided with the introduction of the HIGH Amp alternator fitment from the factory.
As said, I believe your engine has the 4 V style belts, with the closest to the engine being thinner (not so thick) as the other 3.
This parts snap shows what the words are attempting. #13 is the laminated section, and #15 is the pulley pack, simple now.
I drew my lines as you can see and when to run HER,,,, click click click click cliiiiiick...! That ****... So I didnt check the slippage, YIT! Going out to do that today. Overnight shifts out of the blue throws and old man like myself. BUT I'm heading out for a little more pain, today...
What about the SEAL? The one in the link above?
If I have the sliiiiiping inner belt drive and delamination, I want to send out the pully to Dale Industrial ASAP... I have/want to drive her out to Pittsburgh at the end O the month and having all parts here (new seal) would be great! Ball joint bolts are between here and the UK, somewhere... Lol, it's all coming "together"... From Portland/Salem Oregon to London UK. Alllll coming together... Sheeeeesh... What have I gotten myself inTA?!
****** SHOOT!!! I just looked better at the picture below,,,, and yes,,, I think you are right... The flat belt to the left seems to take up the whole of laminated belt section...
pS... I am very interested in the HIGH amp alt. Can they be fit to the 1990?
Is that the separation of the sections?? Blue circle???
I see it now,,, said the blind man.
Last edited by JayJagJay; 04-12-2020 at 01:14 PM.
#24
I think you answered your own question.
Its been "sqealing" and getting worse, is either of 2 things.
1) Delaminating pulley
2) Alt belt waaaaay past its use by date.
NOTHING to do with steer etc as the alternator belt on the V12 is for the alternator ONLY. OK, the went Serpentine on the later engines, but we are talking the basic engine with 4 "V" belts as factory.
Its been "sqealing" and getting worse, is either of 2 things.
1) Delaminating pulley
2) Alt belt waaaaay past its use by date.
NOTHING to do with steer etc as the alternator belt on the V12 is for the alternator ONLY. OK, the went Serpentine on the later engines, but we are talking the basic engine with 4 "V" belts as factory.
#25
OK,
Your car confuses me a tad.
7th coffee, so look out.
IF you have a "flat" belt nearest the engine for the alternator only, then as best I know, you have the 110amp alternator?????, but your market did not always get what the rest of us got, and vice versa.
That is why they went to the flat belt, more "V" sections to drive the higher load requirements of that alternator.
BUT
The tension of that belt is CRITICAL. It will slip and slide if too loose, and too loose may only be one rotation of the adjuster nut.
AND
Grease and grime is NOT their friend at all. The multi "V" pullies get gunked up, and that stops the drive, and creates squeal.
I suggest a GOOD degrease, wash it down, degrease again, pay attention to those pullies, make sure they are CLEAN.
I fitted the 110amp to mine, and drove it with a standard V belt, but tension was critical also, and that belt did wear out slightly quicker than the others, but, I only leave any belt 5 years tops.
My notes list a 5PK0825 as the flat style bet for that position.
Your car confuses me a tad.
7th coffee, so look out.
IF you have a "flat" belt nearest the engine for the alternator only, then as best I know, you have the 110amp alternator?????, but your market did not always get what the rest of us got, and vice versa.
That is why they went to the flat belt, more "V" sections to drive the higher load requirements of that alternator.
BUT
The tension of that belt is CRITICAL. It will slip and slide if too loose, and too loose may only be one rotation of the adjuster nut.
AND
Grease and grime is NOT their friend at all. The multi "V" pullies get gunked up, and that stops the drive, and creates squeal.
I suggest a GOOD degrease, wash it down, degrease again, pay attention to those pullies, make sure they are CLEAN.
I fitted the 110amp to mine, and drove it with a standard V belt, but tension was critical also, and that belt did wear out slightly quicker than the others, but, I only leave any belt 5 years tops.
My notes list a 5PK0825 as the flat style bet for that position.
Last edited by Grant Francis; 04-12-2020 at 10:14 PM.
#26
OK,
Your car confuses me a tad.
7th coffee, so look out.
IF you have a "flat" belt nearest the engine for the alternator only, then as best I know, you have the 110amp alternator?????, but your market did not always get what the rest of us got, and vice versa.
That is why the went to the flat belt, more "V" sections to drive the higher load requirements of that alternator.
BUT
The tension of that belt is CRITICAL. It will slip and slide if too loose, and too loose may only be one rotation of the adjuster nut.
AND
Grease and grime is NOT their friend at all. The multi "V" pullies get gunked up, and that stops the drive, and creates squeal.
I suggest a GOOD degrease, wash it down, degrease again, pay attention to those pullies, make sure they are CLEAN.
I fitted the 110amp to mine, and drove it with a standard V belt, but tension was critical also, and that belt did wear out slightly quicker than the others, but, I only leave any belt 5 years tops.
Your car confuses me a tad.
7th coffee, so look out.
IF you have a "flat" belt nearest the engine for the alternator only, then as best I know, you have the 110amp alternator?????, but your market did not always get what the rest of us got, and vice versa.
That is why the went to the flat belt, more "V" sections to drive the higher load requirements of that alternator.
BUT
The tension of that belt is CRITICAL. It will slip and slide if too loose, and too loose may only be one rotation of the adjuster nut.
AND
Grease and grime is NOT their friend at all. The multi "V" pullies get gunked up, and that stops the drive, and creates squeal.
I suggest a GOOD degrease, wash it down, degrease again, pay attention to those pullies, make sure they are CLEAN.
I fitted the 110amp to mine, and drove it with a standard V belt, but tension was critical also, and that belt did wear out slightly quicker than the others, but, I only leave any belt 5 years tops.
Confuses me too.
Was messing around with it today...
I have a 115 amp alternator.
Had to jump it today and after I did and removed the cables,,, voltage dropped down to nothing and she quit. Jumped her again,,, left cables on a while after she started. Left them a good while. Took them off. Voltage stayed at 14v (normal) with no accessories on. None.
Waited a while and voltage started to drop and stayed at about 13.4, 5 and 6 volts. Started turning on lights, voltage dropped. Turned on HVAC blowers, waaaay down to under 12v. Mashed brake,,, 11.5, 6 and 7. No good.
I did exactly what you said and degreased the belt. As best I could reach it. The belt was replaced 2-3 yrs ago (gates belt) and I have not driven the car in any considerable way... But that belt is worn and was gummed up .
I found ZERO balancer movement off of those marks. None. I had her idling a good 30min today, reving the motor by hand. All that voltage flux was happening without balancer slipping/delamination fault as far as I could tell. Confused there too.
I wasn't able to get the battery today. Will tomorrow along with a new belt. I'll change the belt and battery and see where that leaves me FIRST,,, before any steps at taking off the balancer.
I feel like I'm chasing my tail and dragging you all along with me. Sorry bout that.
#27
OK, beer o'clock here now, and my X Type needs some TLC.
Pulley appears OK.
Belt gummy etc is either from the oil, and wrongly tensioned, as in too loose, and overheated that belt.
Battery is still suspect, and when that is replaced with the known good one, and the belt situation sorted, then the process starts.
Mine with the XJ40 110 alternator sat at 13.8v at idle, and dropped to 12.9v at idle with a/c, thermo fans, heater rear window, all on. Raised the revs to 1200, 13.8v flat. If yours still drops like a rock, you have wiring issues, and it may be the +ve side, or the -ve side, and that tracing will take TIME.
I still suspect the belt has caused the battery to go off, and will wait and see what you find.
Make sure you clean all those little "V" grooves BEFORE you replace that belt, on BOTH pullies.
Back later, stuff needs doing.
Pulley appears OK.
Belt gummy etc is either from the oil, and wrongly tensioned, as in too loose, and overheated that belt.
Battery is still suspect, and when that is replaced with the known good one, and the belt situation sorted, then the process starts.
Mine with the XJ40 110 alternator sat at 13.8v at idle, and dropped to 12.9v at idle with a/c, thermo fans, heater rear window, all on. Raised the revs to 1200, 13.8v flat. If yours still drops like a rock, you have wiring issues, and it may be the +ve side, or the -ve side, and that tracing will take TIME.
I still suspect the belt has caused the battery to go off, and will wait and see what you find.
Make sure you clean all those little "V" grooves BEFORE you replace that belt, on BOTH pullies.
Back later, stuff needs doing.
Last edited by Grant Francis; 04-13-2020 at 02:52 AM.
#28
OK, beer o'clock here now, and my X Type some TLC.
Pulley appears OK.
Belt gummy etc is either from the oil, and wrongly tensioned, as in too loose, and overheated that belt.
Battery is still suspect, and when that is replaced with teh known good one, and the belt situation sorted, then the process starts.
Mine with the XJ40 110 alternator sat at 13.8v at idle, and dropped to 12.9v at idle with a/c, thermo fans, heater rear window, all on. Raised the revs to 1200, 13.8v flat. If yours still drops like a rock, you have wiring issues, and it may be the +ve side, or the -ve side, and that tracing will take TIME.
I still suspect the belt has caused the battery to go off, and will wait and see what you find.
Make sure you clean all those little "V" grooves BEFORE you replace that belt, on BOTH pullies.
Back later, stuff needs doing.
Pulley appears OK.
Belt gummy etc is either from the oil, and wrongly tensioned, as in too loose, and overheated that belt.
Battery is still suspect, and when that is replaced with teh known good one, and the belt situation sorted, then the process starts.
Mine with the XJ40 110 alternator sat at 13.8v at idle, and dropped to 12.9v at idle with a/c, thermo fans, heater rear window, all on. Raised the revs to 1200, 13.8v flat. If yours still drops like a rock, you have wiring issues, and it may be the +ve side, or the -ve side, and that tracing will take TIME.
I still suspect the belt has caused the battery to go off, and will wait and see what you find.
Make sure you clean all those little "V" grooves BEFORE you replace that belt, on BOTH pullies.
Back later, stuff needs doing.
Good rest O the day to ya!!!
Midnight here...
#29
#30
Thank you Greg...
I've cleaned up fire wall connects on both sides but not under - alt to starter motor - but will, and replace belt and bat ASAP... The alt was ordered on Rock a year ago and, if push comes ta,,, I'll see about the warranty! Pouring rain here today which doesn't make for good outside car weather - so I'll re-vinyl two rear Porsche interior quarter panels inside, instead, lol... These machines are running my life, lol
#31
#32
Join Date: Mar 2008
Location: Pacific Northwest USA
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While you're down there......
Disconnect the alternator-to-starter cable at both ends and use an ohmmeter to check the resistance. It may be corroded and not carrying current very well.
This is something that has come up on Series III XJ6s a very few times over many years but I happened to be involved with just such a scenario on a friend's car. Long story short, the cable had very high resistance. The cable was hopelessly corroded....visually apparent only by cutting the insulation off. The wiring strands had, basically, turned to green crud; almost totally destroyed.
Cheers
DD
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#33
While you're down there......
Disconnect the alternator-to-starter cable at both ends and use an ohmmeter to check the resistance. It may be corroded and not carrying current very well.
This is something that has come up on Series III XJ6s a very few times over many years but I happened to be involved with just such a scenario on a friend's car. Long story short, the cable had very high resistance. The cable was hopelessly corroded....visually apparent only by cutting the insulation off. The wiring strands had, basically, turned to green crud; almost totally destroyed.
Cheers
DD
Disconnect the alternator-to-starter cable at both ends and use an ohmmeter to check the resistance. It may be corroded and not carrying current very well.
This is something that has come up on Series III XJ6s a very few times over many years but I happened to be involved with just such a scenario on a friend's car. Long story short, the cable had very high resistance. The cable was hopelessly corroded....visually apparent only by cutting the insulation off. The wiring strands had, basically, turned to green crud; almost totally destroyed.
Cheers
DD
And remove, inspect and see if I can match the cable up and replace - if need be... Maybe I just should.
The voltage and charging situation, has always been a situation. Now that I'm on the road (kinda and sometimes) it's an impossible situation. It would be so nice to have it RIGHT once and for all!
#34
Remember JJJ, there is no mystery or magic involved; if a system is correct it will perform correctly. It is just a matter of patiently going through the various components and ensuring they are to spec. Obviously on a V12 installed in an XJS you have access problems which make the fixing process much more difficult than in an engine bay with decent access; but the truth remains - go through the system and the problem will be fixed. Forget eureka moments, just grind away!
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Grant Francis (04-13-2020)
#35
Remember JJJ, there is no mystery or magic involved; if a system is correct it will perform correctly. It is just a matter of patiently going through the various components and ensuring they are to spec. Obviously on a V12 installed in an XJS you have access problems which make the fixing process much more difficult than in an engine bay with decent access; but the truth remains - go through the system and the problem will be fixed. Forget eureka moments, just grind away!
And not close to giving up. Just starting to have fun, actually...
Was in Brooklyn the other day, drove to the beach, top down with my girl. People saying hi, just because of the car, with questions. Others, folks who also do there own work on classics, wanna stop and talk. It's alllllllllll good! Plus the learning, plus the sanity of time spent with myself, doing something. Plus the COST,,, ooops,,, did I just say cost? Lol. OMG
It's pouring rain here today. But, just picked up the AGM battery and new belt. Tomorrow I jack her up, inspect the cable from starter to alt to get an idea, if needed, remove it for length and replace. Then do the belts and clean things up as y'all suggest/make clear. And get it right. Charging problems. Then see what's next. And there will be a next.
I probably have a HORRIFIC relay somewhere reeeeeking electrical load havoc. We'll see.
I thank you guys. Really! It's not lost on me how challenging or near impossible this would be without every last one ah ya!
Can't resist it...
Ride height came up in the back after some driving...
Last edited by JayJagJay; 04-13-2020 at 01:45 PM.
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Greg in France (04-13-2020)
#36
Join Date: Jul 2012
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Two places to check. And one of those to fix!!!
Boot. The battery - is attached to the chassis .
Engine bay: Add a ground cable, not a mere wire from engine to chassis.
Why? Because the alternator is grounded to the engine, The engine to chassis ground is poor.
This cable will fix that. A bit imperfect, but works!!!
In the best of times, the battery - would connect to the engine!! All the other odd here and there grounds would connect to the engine, not the chassis
Doing that to my lump fixed so much!!!!! A n ice healthy cable from chassis to the alternator mount on the engine! handy in my engine bay.. The battery is housed there...
Carl
Boot. The battery - is attached to the chassis .
Engine bay: Add a ground cable, not a mere wire from engine to chassis.
Why? Because the alternator is grounded to the engine, The engine to chassis ground is poor.
This cable will fix that. A bit imperfect, but works!!!
In the best of times, the battery - would connect to the engine!! All the other odd here and there grounds would connect to the engine, not the chassis
Doing that to my lump fixed so much!!!!! A n ice healthy cable from chassis to the alternator mount on the engine! handy in my engine bay.. The battery is housed there...
Carl
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#37
Two places to check. And one of those to fix!!!
Boot. The battery - is attached to the chassis .
Engine bay: Add a ground cable, not a mere wire from engine to chassis.
Why? Because the alternator is grounded to the engine, The engine to chassis ground is poor.
This cable will fix that. A bit imperfect, but works!!!
In the best of times, the battery - would connect to the engine!! All the other odd here and there grounds would connect to the engine, not the chassis
Doing that to my lump fixed so much!!!!! A n ice healthy cable from chassis to the alternator mount on the engine! handy in my engine bay.. The battery is housed there...
Carl
Boot. The battery - is attached to the chassis .
Engine bay: Add a ground cable, not a mere wire from engine to chassis.
Why? Because the alternator is grounded to the engine, The engine to chassis ground is poor.
This cable will fix that. A bit imperfect, but works!!!
In the best of times, the battery - would connect to the engine!! All the other odd here and there grounds would connect to the engine, not the chassis
Doing that to my lump fixed so much!!!!! A n ice healthy cable from chassis to the alternator mount on the engine! handy in my engine bay.. The battery is housed there...
Carl
I have a second engine to chassis ground bolted in at the alternator and tied in at a good point on the chassis and your right, it did help a LOT when I did it...
#38
SHOULDAH SEEN THE OTHER GUY!!!
A 6th or a 7th of the belt looked this way...if you can zoom to make it out...?
The ribs were cut SUPER deep into the belt... especially compared to the new one.
I get a certain amount of satisfaction out ah taking a pair of heavy wire cutters and just SNIPPING an old belt to "remove" it.
I have NEVER seen a bolt as impossible to get to as this alternator belt tensioner...crazy!
New AMG battery in possession. I didn't want to return a battery fully charged to redeem my warranty, ya know. The game... So I intentionally ran the battery down. Turn key to iii,,, lights on,,, fans on high. Took all of four minutes, maybe three, before the battery went to low nothing dead.
Got about half way thru and the sun went down. Didn't take long. Still need to clean, tighten belts see what the wires look like under the car. Tomorrah.
A 6th or a 7th of the belt looked this way...if you can zoom to make it out...?
The ribs were cut SUPER deep into the belt... especially compared to the new one.
I get a certain amount of satisfaction out ah taking a pair of heavy wire cutters and just SNIPPING an old belt to "remove" it.
I have NEVER seen a bolt as impossible to get to as this alternator belt tensioner...crazy!
New AMG battery in possession. I didn't want to return a battery fully charged to redeem my warranty, ya know. The game... So I intentionally ran the battery down. Turn key to iii,,, lights on,,, fans on high. Took all of four minutes, maybe three, before the battery went to low nothing dead.
Got about half way thru and the sun went down. Didn't take long. Still need to clean, tighten belts see what the wires look like under the car. Tomorrah.
Last edited by JayJagJay; 04-13-2020 at 09:30 PM.
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Dukejag (04-14-2020)
#39
I am holding my breath!!!!
Is it morning yet.
Once fixed you will be proud as punch!
I have replaced all my belts and tightened them with the old can you turn the belt 90deg trick.
Without any noise the power steering was hard and wife complained, hell I just thought that was how it was being an old car, tightened the belt a bit more and go to go...seriously night and day difference what a turn on the tighten nut made.
good luck!
Is it morning yet.
Once fixed you will be proud as punch!
I have replaced all my belts and tightened them with the old can you turn the belt 90deg trick.
Without any noise the power steering was hard and wife complained, hell I just thought that was how it was being an old car, tightened the belt a bit more and go to go...seriously night and day difference what a turn on the tighten nut made.
good luck!
Last edited by Dukejag; 04-14-2020 at 03:20 AM.
#40
Seen that a few times in my past.
Previous "mechanic" DID NOT clean ALL the grooves in the pullies prior to fitting the new belt. The old bits of belt etc simply chewed up the new belt.
You need to sit down and take one of those "toothbrush" size wire brushes, and carefully clean ALL the grooves etc on the crank pulley and the alternator. NO shortcuts.
THEN
As Duke said, tighten the new belt, run it an hour or so, then tighten it a tad more.
There are special gauges etc for this, HAHA, I dont even have an OBD reader, OLD school, very old, common sense, and being a 5PK flatty, and short as they come, you will need ABOUT 3-4mm deflection with a FIRM push of the thumb. Check it again after another 4-5 hours of use.
These belts will slip and slide if too loose, and too loose is only 1 turn of that adjuster nut, the easy to get at one.
Previous "mechanic" DID NOT clean ALL the grooves in the pullies prior to fitting the new belt. The old bits of belt etc simply chewed up the new belt.
You need to sit down and take one of those "toothbrush" size wire brushes, and carefully clean ALL the grooves etc on the crank pulley and the alternator. NO shortcuts.
THEN
As Duke said, tighten the new belt, run it an hour or so, then tighten it a tad more.
There are special gauges etc for this, HAHA, I dont even have an OBD reader, OLD school, very old, common sense, and being a 5PK flatty, and short as they come, you will need ABOUT 3-4mm deflection with a FIRM push of the thumb. Check it again after another 4-5 hours of use.
These belts will slip and slide if too loose, and too loose is only 1 turn of that adjuster nut, the easy to get at one.
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