My buddy is either bored or needs attention. We were not able to track down the source of a small boost leak he has, only hits about 10psi. We think it may be a small leak in gaskets.
Last time we wrenched around we went exploring with a scope and found a lot of carbon build up in the charge coolers.

Between the SC having almost 100k, a suspected small leak, carbon in IC and finding coolant in valley he decided to tear it apart down to the heads.

He already put a big list of parts together but I recall people using the intake gaskets from the 4.2l.

Does anyone have the gasket numbers for the parts used from the 4.2?
Metal intake gasket, guessing 2 each?
are there upper and lower?
New head bolts?
Anything else that should be upgraded?

Also, seen Vic Reins (sp?) gaskets. Anyone know what is deal with these?

Any help is appreciated.

 

Carbon in the charge coolers? The only thing running through them is air. There is no combustion or fuel going through them, just boosted air and a little oil injested by the s/c. I could see carbon build up on a cyl head combustion chamber or valves as a by-product of combustion and hydrocarbon based fuel but not in the air charge coolers.

 

It's just engine oil that's being ingested into the intercooler via the part load breather. When I had the heads off my 98' with 234K miles, I sprayed a total of 2 cans of easy off oven cleaner into each IC. When I was done, they looked great. I also didn't want all the oil going back into the intercoolers so I rigged up an oil catch can and it's working great also. Btw, I didn't use the intake manifold gaskets off the 4.2 so I can't help you there.

 

Yes, carbon in intercoolers. Pretty bad, wish I had a pic.

There is a trail coming from the EGR into the throttle body and down the intake elbow to the SC. From there up and into the chargers.

My guess is that on bank 1 (passenger) there is a bad injector or even bad coil. Injector is spitting and not burning well causing some of his poor mileage (14-15mpg) and the rich un-burnt mix goes back through the EGR and back into the intake, further creating a rich condition and cycle continues. Bad injector+ bad/stuck EGR, atleast that is my theory.

 

The carbon is from the exhaust gas that goes through the intercoolers via the EGR valve. Those of you claiming no carbon in the intercoolers do know what EGR is? EXHAUST gas recirculation. There's also plenty of oil from the part load and full load breathers. I installed an oil catch can and it fills up quite quickly.
The oil combined with carbon leaves a nasty coating inside the intercoolers.

10 psi is not too bad. I believe the official Jaguar number for boost pressure was 11.6 psi.

 

If you research on this forum in the X350 section you will see that the consensus, for the X350 at least, is that the carbon build up is from the high load breather and not the EGR or the low load breather.

I have been running an oil catch can on both the high and low load breather pipes and am collecting quite a bit of oil in the high oil catch can and none in the low catch can.

My intercoolers were pretty bad when I did an SC swap at about 100k and my intake elbow was also caked with almost about 1/8" of carbon.

 

Any reason the breathers dump so much oil back in? I'm assuming its due to vacuum from SC.

I thought stock was 12psi, close. I think he is pulling more in the high 9 range, barely touching 10. I didn't partake in that part so don't know.

Either way, the IC is clogged up bad. I'll see if I can get a pic.

 

It was silly to claim that no carbon goes through the intercoolers, whether the majority of carbon comes from the EGR or full load breather. Interesting, I haven't seen this claim that the carbon comes from the full load breather instead of the EGR. On my car the carbon buildup was heaviest in and closest to the EGR, so it stands to reason that is where it comes from. That's exactly what the EGR does after all.

In ROW markets, I know some previous models such as mine came without EGR. Do those cars have the same carbon buildup?


Sandurz, I think it's normal for oil to come from the breathers even on healthy engines; Jaguar or other makes. Most people don't know just how much goes through since they don't install catch cans. Even with a low 60k miles I need to empty my catch can on my part load breather every 1500-2000 miles.

 

There was a (parts) TSB for the upgraded SC outlet coupler assy. The 2 plates and the 2 rubber seals were redesigned to better seal the coupler area.

bob

P.S. Does ANY ONE ever read the TSBs besides me???

 

Who is claiming that no carbon goes thru the intercoolers?

The carbon is from oil deposits. The EGR gases do not help however the bulk of the oil is from the PCV valve ( High load breather) side on an X350 where that line dumps directly into the elbow under the throttle body before passing through the super charger and then the intercoolers.

The high load breather has significantly more vacuum than the low load breather.

Is the X380 significantly different?

The only time I had any oil on the low load breather side oil catch can was when there was a blockage on the high load breather side.

 

A couple posters above, not you.

It's different on 4.0 V8's. The full load breather dumps into the intake tube after the MAF and before the TB. It's not under vacuum. In fact, fresh air travels the other way when not under full load. The part load connects to the elbow after the TB and is under vacuum.

Since the engine isn't under WOT very much, most of the oil comes through the part load breather since that's where it spends the vast majority of operation- under part load.

 

. If you read back you can CLEARLY see "WHO" (passive aggressive responses are so drool on forums) air mixed in with some vacuum suction oil passes through the intercooler, there is no part of the combustion process (hydro carbon fuel) going on in there. If your EGR gases and vacuum sucked in oil is heating up in your air charge COOLER (see that's a key word, cooler) and turning into carbon on them you've got other problems with your car, it's servicing habits and maybe how up to snuff your cooling system, intercooler system is. Next time you want to ask "Who" just look up and call me out, don't try to be aloof. Everything on my XJR was off at 51k, yes, there was fresh, clean oil residue in the s/c and coupler elbows, barely any EGR "soot" in and around the EGR and whistle clean air charge coolers ( although an oil film present) . It takes a hell of a lot of heat in the combustion chamber/head to carbon the chamber/piston top and valves and even that can be prevented by running cleaner fuels, clean, up to snuff PCV, properly working EGR and consistent, quality oil changes. Once again, if your getting things that hot and sucking in that much oil to where it's carbonizing in the air charge coolers (not to be confused with caked on oil/dirt debris) you need to have your cars systems checked out.

 

WOW! "Passive aggressive responses as so drool" .I thought I was being accused of "lack of knowledge" by Steve M. I seem to have hit a nerve.

Btw IF you were to research this issue of intercooler, throttle body, and elbow "clogging" you would find it a common one on forced induction engines. The gunk in the intercoolers is not the same as the carbon deposits on pistons.

The people in this forum who have installed oil catch cans are well aware of the issue.

 

The other problem with your theory is that the hottest oil/EGR air would be at the departure of the supercharger where it hits the coupler elbows prior to entering the air charge matrix not at the air charge matrix with airflow/coolant circulation. Why then would heat transfer to carbonization of the oil/EGR deposits there yet not a thing at the hotter, same air, departure elbow?

 

Wouldn't know what SteveM posted as he's on my ignore list. I foresee someone else headed there soon. You are confusing oil/dirt contamination with "carbonization"

 

You said " who said carbon doesn't go through the intercoolers" I DID, now your saying its gunk NOT the same as cylinder carbonization. Once again I SAID IT because it isn't CARBON it's GUNK. In YOUR own words. You're calling people out for stating the truth then getting mad because they are defending their stand.
Carbon IS carbon, Gunk is Gunk, there IS a difference. Especially when you say someone is wrong, when they are not!

 

I read and collect them every time you post them ... and click
the thanks button if I am logged in

ps. my hard drive is a mess

 

I agree that the hottest air is where the EGR exhaust gases go into the elbow where they meet with oil discharge from the breather , high load on my X350 SC, and air fuel mixture drawn down thru the throttle body.

On my TB below the butterfly there was some build up of "carbon" but a thin layer. Above the butterfly it was clean.

On my car the elbow "gunk" was the closest to carbonization but still not as hard as what you can find on a piston.

As you know the mixture flows through the elbow into the SC and is pushed through the intercoolers where the surfaces hopefully are a lot cooler but the fins inside can get coated easily with oil deposits.

My EGR tube itself had no deposits in it whatsoever when I pulled it off at about 100,000 miles unlike my elbow which was badly caked as you could see in the pic I posted.

When I detached my high load breather tube oil actually dripped from the end that attaches to the PCV. Thats why I installed an oil catch can.

Maintenance wise I keep my car tip top and use Shell V power 93 most of the time.

Even with the mods I have done I get around 15 - 17 mpg around town and that always includes several moderate runs. Recently on a 450 mile trip averaging 63 mph I got 26+ mpg. The point is I think my engine is performing very well.

 

+1

oh, on both points, so I suppose +2.