When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Hello, I own a Jaguar S-Type 2.5 V6 from 2002, Racing english green tan interior second generation. Since I bought the car I always counted reading this forum to solve problems and do it my self because of the money. But now I really don't know what to do anymore, my girlfriend whats to sell it or send down a cliff cause she reached is limit and hates the car by now...
The car is acting erratic and doesn't has aceleration, stutters, not on Limp mode. during driving and . The symptoms are:
- Rought idle (RPM are low - around 750rpm's or less);
- Engine shakes when parked or during a Stop sign;
- Gas consuption above average;
- Smell of gas (may be too rich mixture or unburned);
- Tail pipes popping sound;
- Not a smooth ride while driving...
The OBD computer test gave the following errors:
- P1582 (Electronic Throttle Monitor Data Available); See P.S bottom message
- P0205 (Injector Circuit Malfunction Cylinder 5);
- P0300 (Random Cylinder Misfire Condition);
- P0301 (Cylinder 1 Misfire Detected);
- P0302 (Cylinder 2 Misfire Detected);
- P0305 (Cylinder 5 Misfire Detected);
- P0306 (Cylinder 6 Misfire Detected);
- P1316 (Misfire Excess Emission);
- P1549 (Lower Intake manifold Valve Tuning (or IMT) malfunction); See P.S bottom message
- P1000 (dont know...).
- U1027 (Invalid or Missing Data for Engine RPM);
- B1676 (Battery Voltage Out of Range).
P.S: Today I rewired the bottom throttle connector (was smashed) and the lower IMT valve circuit (wires were broken) and installed a new lower IMT valve( just in case) and new blued Oring on both lower and upper IMT valves but the problem persists...
Cheers from Algarve, Portugal
Guilherme Ribeiro
Last edited by GGG; 11-05-2021 at 08:44 AM.
Reason: Reduce image size
Yes, its an on going battle... recently work was done. I changed almost everything on the engine about 7.000kms ago, rebuilt... piston rings head gaskekts, new spark plugs, new coils,new knock sensors, oil pump, crankshaft caps, all valves turned, timing chain kit, new injectors and more and more. The thing persist and i dont know what it is.... The last thing i changed a week ago was the lower and upper intake manifold gaskets (6 bellow and 6 upper) cause i suspected of an air leak and the IMT orings and lower valve(IMT) because of the P1549.
I suspect of the injectors female plugs harness, there are some of them that wont click and easly can come loose giving the error P0205 on injector 5. But I dont know...
Last edited by Guilherme Ribeiro; 11-05-2021 at 04:17 AM.
You now have two threads running on essentially the same topic; this will turn into a mess... Perhaps a moderator can merge the two as it appears that information needed to help this forum member is contained in both posts.
After the extensive work done on your engine, it is kind of tough to know where to being, but here goes:
1. Your battery voltage is out of range; this needs to be sorted first, as S-types are very sensitive to this.
2. Coil packs were replaced; were the new coils OEM (e.g. Denso, NGK) or cheap Chinese knock-off parts?
3. Have you run a compression test of the the "ring and valve job"?
4. Are all the sensors and connectors properly installed on the engine?
I Have 3 new original Fomoco/Jaguar Ignition coil on Bank 1 and 3 new NGK ignition coil on bank 2. Never made a compression test, also the battery is also new(1 year and a half) and from a top brand. I suspect the alternator is faulty (P1632 voltage regulator). Meanwhile, Today I went to see the injectors connectors plugs (cause of the P0205 error) and all each one of the 6 injectors had a broken connector, not even one made that "click" sound . Bought today a injector harness for 25€ and tomorrow I will rewire and reconnect with the new ones to see what happends...
Curiosity: One of the new ignitions coils that I bought a few months ago (NGK), well today I saw that the top(the shinny black finish) of one of the ignition coils was swollen and raised compared to the others from NGK. Any tip or hear anything about it?
Last edited by Guilherme Ribeiro; 11-05-2021 at 08:51 PM.
From what I understand, this code means the generator is not sending proper feedback to the ECM, for fine-tuning idle speed, fuel scheduling, etc. If not working properly, I'm not sure you'd even be aware of the problem.
Do make sure the charging system is working properly. Voltage out of specs can cause all sorts of strange behavior. Hook up a voltmeter at the battery terminals. I believe your car has the late-model smart charging system. Immediately after start, you should see about 14.5V, tapering down to around 13.5 after a few minutes.
I would also recommend charging the battery. You can't rely on the alternator to have kept the battery fully charged, especially if not driven much lately.
Originally Posted by Guilherme Ribeiro
Meanwhile, Today I went to see the injectors connectors plugs (cause of the P0205 error) and all each one of the 6 injectors had a broken connector, not even one made that "click" sound ...
The two injector fault codes (P0201 and P0205) are a big clue. After checking the charging system, this is where I'd concentrate my efforts. Please be aware the lack of proper locks on the connectors may not necessarily cause trouble. As long as the individual terminals are still making a good connection, the injectors should operate properly. The locks are important to keep the connectors from working loose eventually, but if still making a good connection electrically, the broken locks by themselves are not an immediate problem.
I suggest investigating the injector fault codes first because those are what I consider "primary" faults. An injector that isn't firing (for whatever reason) will definitely cause reduced power output from that cylinder. The computer is smart enough to give more details, i.e. something isn't right in the control circuit or the electrical side of the injector itself. The ECM is saying you've got a bad input into the power equation. At the same time, the misfire codes (P0300 through P0306) are "secondary" faults, meaning reduced power has been sensed from those cylinders, but without knowing exactly why. Misfire codes are basically a measure of power output for the individual cylinders.
This is a good time for me to get up on my Misfire Soapbox™. If the computer has set a misfire code, please be aware "misfire" wasn't the best terminology that could have been used. Misfire sounds like an ignition problem, at least to me, meaning the fuel and compression were there, but for whatever reason, the required spark was missing or weak. This might lead a good-looking aspiring mechanic to troubleshoot the daylights out of a perfectly good ignition system. I do not care to discuss how I know this.
In OBD-speak, misfire simply means one or more cylinders is putting out low power compared to the others. Pretty much anything affecting the output of a cylinder can set a misfire code. It can be low compression. It can be a valve not opening fully. It could be a bad fuel injector or no signal for it to open. And yes, it could be an ignition problem, too, but don't overlook the other possibilities, too. [/soapbox mode off]
Originally Posted by Guilherme Ribeiro
Curiosity: One of the new ignitions coils that I bought a few months ago (NGK), well today I saw that the top(the shinny black finish) of one of the ignition coils was swollen and raised compared to the others from NGK.
Yes, its an on going battle... recently work was done. I changed almost everything on the engine about 7.000kms ago...
Ah, another big clue, leading to another question. What symptoms prompted you to tear the engine apart? Did you have the same rough running and lack of power before all of this work?
As previously suggested, a compression check is highly recommended. Maybe some of the new rings didn't seat properly, or something like that. You'd be chasing your tail trying to resolve external issues (injectors, coils, etc.) if compression is not up to specs.
Before the tear down the car had a head gasket situation(water and a sweet smell from coolant on the tail pipes) and was showing the same type of symptoms as now(ensine shaking and some rough idleling/misfire). Today i Will reconnect all the new injector plugs, problem or not it has to be done... Also, can a low compression give injector faults? (P0205 P0201) Next week I will make a compression test, test all the ignition coils one by one and the injector number 5 and may be all of them (resistance). Also, Do you advice buying a new alternator?
P.S: Engines with low compression in any cylinder obrigatory consumes oil? I ask that cause during the 7 months since the tear down he alway stuck to the same top oil level and clean oil.
Also,i forgot to mention that a week ago when I started the car for the first time after changing the lower and upper intake manifold gaskets,the RPM neddle was moving up and down between 1200RPM-1800RPM during driving on her own, next day stop doing that.
Last edited by Guilherme Ribeiro; 11-06-2021 at 09:43 PM.
Before the tear down the car had a head gasket situation(water and a sweet smell from coolant on the tail pipes) and was showing the same type of symptoms as now(ensine shaking and some rough idleling/misfire)…
Ah, another big clue. Did you have the heads resurfaced, or at least check them for flatness? If not, there is a very good chance at least one head was warped, which caused the original failure of the head gasket. Your new head gasket(s) may have likewise failed. A compression test will tell for sure.
Also, do a cooling system pressure test to verify the integrity of the system. This uses a handheld tester that looks similar to a bicycle tire pump. You apply a specified pressure and make sure it holds for at least 15 minutes.
One last test for a possible head gasket failure: Check for combustion byproducts in the cooling system. This tester looks like a turkey baster and has a chamber holding some special test fluid. You run the engine for several minutes with the cooling system cap loosened. Then you carefully remove the cap and draw air from the cooling system into the tester. If exhaust is present, the test fluid changes color.
Why the injector fault codes now? No idea, most likely something was disturbed during all the recent work. But after learning a head gasket had previously failed, there’s a very good possibility the new one has also failed unless the heads were machined flat. Rule that out before digging deeper elsewhere.
No, not at all. That one code was a very minor one, related to feedback for electrical load. It’s not going to cause performance issues, unless somehow the battery wasn’t getting a proper charge.
You can rule out this remote possibility by charging the poor battery and seeing if there is any change. I keep harping to charge the battery as these cars are prone to setting spurious fault codes due to low system voltage. I doubt this will cause the rough running, so don’t get your hopes too high. But do charge that poor battery. It’s a prerequisite for any electrical troubleshooting.
Both heads were machine resurfaced yes, new head bolts were installed and torqued by the book order (Jaguar S-Type 2002.5 book or something like that...), all intake/exhaust valves were hand turned and new valve seals instaled on them. This week i will make a compression test just to be sure..
I didnt make the turkey baster test yet because I think that will give me a false positive reading cause i reused a small proportion of the old coolant on the actual coolant.
Also, today I bought a muItimeter and checked the resistance of the injectors, all of them gave me 14 Ohms, so the P0205 and P0201 error can only be from the wiring, dirty injector (i doubt) or from the broken connector (all my connectors were broken, maybe this one was loose i dont know..). Because a week ago when I starter the car the RPM needle was dancing and bouncing up and down by her self, dont know if has any relation to the injector fault because during the next day she stopped doing that.
Also, I checked the ignition coils resistance today, 7 months ago on bank 1 I installed 3 original Jaguar coils and on bank 2 I installed 3 NGK coils. The resistance readings between the two brands are hugely different, BUT equal between the same brand. One side showing a much higher resistance and the other side showing a much lower resistance. Can this influence anything like misfires or make any engine "imbalanced"?
According to your earlier posts, you are getting misfires on both banks (and consequently both brands of coils), so that would tend to invalidate your multimeter test, no ?
You r righ, it wasnt cause today I rewired the injectors connectors and installed 6 new ignition coils from Jaguar (Denso), bought a CRC electrical spray and cleaned all the possible connectors of the entire car top do bottom. The problem persists, may be is a little bit better now I dont know. Also made a compression test and all the cylinders are within the limits.
Another fact that I saw today, the dashboard instant cosumption is giving me too high readings (during a stop sign at idle sometimes he slowly increased on his own until reaching the max 99L/100, and on the city he was giving me abnormal values of 20L/100) but sometimes he is giving me credible values. The car stinks of unburned gasoline (especially at idle), high abnormal consuption. OBS: During fast acelerations he doesnt vibrate and have power like if he was a normal fix car.
Can it be as simple as a MAP or MAF sensor? Because when I unplugged the MAP sensor during idle, the car didn't showed any symptom or different behavior.
Last edited by Guilherme Ribeiro; 11-10-2021 at 06:37 PM.
Hello again, just made a compreesion test and all the 6 cylinders are showing low compression (80psi the four front and 70psi the two back).
Went do the Jaguar Dealership to make a full diagnosis on their computer machine and they said they didnt found any error code that can be responsible fot the car symptoms.
Any advices? The car shakes, low power, consumes a lot of fuel (and unburned gas smell).
Are you sure the compression readings are correct? With those readings, I can understand that the engine runs rough and lacks power. IIRC a healthy 3.0 should be in the range of roughly 150-180 PSI and anything under 120 should be a cause for concern and further investigation. Variations in compression of 10% or more per cylinder can cause rough running and the car to shake.