I have never used a metal gasket but I don't see any reason why it shouldn't work. It is important to torque the bolts properly and it's not difficult to damage the gasket during assembly.

 

So after confirmation that the non-metal gasket is the correct one I promptly placed an order and it's arriving tomorrow. Then I started looking at the pictures.

The bolt holes don't "appear" to be the same. The metal gasket has one bolt way off to an extended corner. The metal one is what I installed last time and the holes lined up with my throttle body holes. It "appears" as though the non-metal gasket has an offset hole, but not by nearly as much. Should I be concerned?

 

If the metal one fits, the paper one certainly will not.

 

I called the Jaguar dealer again. I gave him my VIN number and asked him to please verify the part number for the throttle body gasket. He confirmed the green one pictured above is the correct gasket.

There is just no way it will fit though. Although mine is NOT an air assisted throttle body, it has the same design and shape as the air assisted throttle body according to the Heritage website. I ordered both gaskets and will send back the incorrect one. I wish motorcarman would happen across this thread, he would probably have run into this before.

The metal gasket won't be here until Wednesday, so if the paper one does not fit tomorrow (which I feel confident it won't), then my car will be down for another day after I take it apart.

I can drive the E30 to work for a couple of days. The A/C works fine as long as I'm going at least 60 MPH. It is still charged with the original R12!

 

Why not just PM motorcarman and ask him?

 

I don't really know him very well, and I imagine someone with as many postings as he could potentially get overwhelmed by newbie questions in his in-box.

 

I hate to speak for the guy but I'm pretty sure like most here, he's here to help. Your call.

 

Both gaskets got here today. The one listed by the Jaguar dealer and most websites, the green paper one, is not even a close fit. It does not line up at all.

I replaced the gasket. The one on there was completely flat, crushed, probably as it should be after installation. The new one still had a noticeable ridge. I torqued the throttle body down onto the new gasket using my torque wrench; about 15 ft lbs.

No noticeable immediate change in fuel trims. When I spray in that area I still get a negative spike in fuel trims, but it's a bit less. Spraying directly onto the sealing edge of the throttle body has no effect on trims, so the new gasket is working fine. If I spray the connection points for the EGR valve nothing changes. If I spray the body of the EGR valve, the black cylindrical portion, then it spikes a little negative again. Could the EGR valve be hopelessly cracked? Man I hate to buy a new one!

Obviously I'll be sending the paper gasket back, question answered...

 

When I removed and cleaned the EGR valve a couple of months ago there was a lot of carbon build-up in the port to the throttle body adapter. It took 45 minutes to get it cleaned out. When i replaced the throttle body gasket today I noticed that build-up has already started to occur again.

Does this mean the EGR valve is not functioning properly?

 

Well, for whoever may be following this particular adventure, I have another update.

I have a rough idle at start-up and a vacuum leak causing positive fuel trims. The spot on the EGR valve where the casing is cracked seems to be where the leak is originating from. I tried sealing it with RTV but the leak didn't go away. I tried a new throttle body gasket since it's so close to that spot; ruled it out at least.

Smoke testing was still not showing any leaks. I increased the smoke test pressure a bit and finally the leak showed itself. It is in FACT the cracked portion of the EGR valve that is leaking, and it's leaking through the RTV. I did a more aggressive job of sealing that spot with RTV and will test again in the morning. That leak would explain the rough idle while the fuel trims adjust at start-up. The EGR valve should be closed at idle but this leak is behind the plunger, so it would leak right into the crankcase during idle.

If I can't patch the leak I guess I'm still looking at buying a new valve. Rockauto seems to have the cheapest one at $231.00.

 

Hi harvest14,

If the EGR valve is operating properly, it seems like you should be able to repair it. Since the EGR valve passes exhaust gasses at pretty high temperatures, silicone sealant may not be able to maintain the integrity of its bond. Even the Permatex high-temp red RTV is only rated to 600F continuous, which is not much higher than the O2 sensor heaters reach just to get the sensors operating properly. J.B. Weld High Heat epoxy is only rated to 550F and only 400F continuous.

I repaired the EGR pipe fitting on one of the exhaust manifolds of our '93 using Blue Magic ThermoSteel and it's held for more than 10 years. It's good for up to 2400F:

https://www.pepboys.com/product/details/9885868/00146


Other possibilities might be:

Permatex Muffler & Exhaust Pipe Sealer:

Permatex Muffler & Tailpipe Sealer (3 oz) 80335/V807: Advance Auto Parts

Permatex Exhaust Pipe Repair Kit:

Permatex 1000 Plus Exhaust Repair Kit: Model# 80334 | True Value


Cheers,

Don

 

I'm pretty sure the RTV is rated to 650 F, like you said. I take it the external part of the EGR valve gets hotter than that?

They sell the Blue Magic product at the local automotive stores around here. If it leaks again I'll pick some up. I guess I should remove the valve to insure I have good enough access to seal it properly. That means more new gaskets. I am keeping gasket makers in business.

By the way, if anyone wants the green gasket from above let me know. Amazon gave me a full refund because their website said it would fit my car, yet they don't require that I send it back.

 

Hi
My XJR is a 99 - and is not fitted with an EGR - so I cant check model specific,
but I was a mechanic with Toyota and a few other dealers - our standard practice for failed EGR was to make a gasket out of heavy exhaust gasket material - and in some cases backed up with a steel shim - also a similar arrangement on the inlet - usually the valve bolts on there, leave any vacuum ports or switching intact if yours does have a vacuum port buy 1X 4mm ball bearing from a bicycle shop. then carry on as normal. The engine ECM should not be aware you have done it, if you are neat - an emissions tester should not pick it. Vehicle manufacturers recycle exhaust gas to reduce emissions - that is not clever at all - check all the gunk in the pipe - that all ends up in the engine - silicon based RTV's are good for any exhaust joint. at the exhaust port temp is 465c - 540c silicon is about 8ooc but it deteriorates over time
Cheers - hope it helps
DC

 

I re-did the smoke test this morning after the RTV dried overnight and it leaks just as bad as it did last night. It actually seems a little worse, however that would be possible.

I guess I'll remove the valve and consider how to repair it better on my work bench. The problem is the darn gaskets are not readily available anywhere in town, not even from the Jaguar dealer. That's one of the frustrating things about working on this car. The parts are usually not prohibitively expensive, but you just can't get anything fast. I'm always waiting......

 

In the U.S. and perhaps elsewhere, Exhaust Gas Recirculation is required to meet ever-tightening emissions standards, mostly driven by CARB, the California Air Resources Board, which has a dominant impact on emissions standards throughout the country because few automakers want to be prohibited from selling cars in California.

If I'm not mistaken, the Engine Control Systems used in Jaguars since at least the late '80s can detect if the EGR valve does not open when instructed to do so by the ECM by checking for the expected change in 02S data, so if you are suggesting that the EGR be blocked, I think a DTC would be triggered and the ECM might default to a less efficient fueling map.


The temperature ratings I gave before were in Fahrenheit. Here are the ratings in both Centigrade/Celsius and Fahrenheit along with the data sheets from which the temps were referenced:

Permatex RTV Black silicone is rated to 204C / 400F continuous:
http://www.devcon.com/prodfiles/pdfs/fam_tds_371.pdf

Permatex RTV Ultra Grey is rated to 232C / 450F continuous:
https://www.permatex.com/wp-content/.../tds/82194.pdf

Permatex RTV Red High-Temp Silicone is rated to 316C / 600F continuous:
http://www.devcon.com/prodfiles/pdfs/fam_tds_376.pdf

According to this link, exhaust gasses in a gasoline/petrol engine burn in the range of 1,000 to 1,400F (538 to 760C):
https://www.reference.com/science/te...3fa1fd9a8e8750

Based on the above, none of these commonly available RTV silicone products is suitable for use in the exhaust gas path. We should also mention that not all silicone sealants are safe for O2 sensors; the fumes from some sealants will ruin the sensors.

Cheers,

Don

 

I removed the EGR valve tonight and scraped off all of the RTV that I had caked on there the last few days. That was fun.

I then sealed all suspect areas that could be responsible for the air leak. I used the Blue Magic Thermoseal high temperature sealant that Don recommended. That's some pretty cool stuff. Easy to apply and it seems to have filled all the crevices and holes nicely. I'm going to let it dry overnight and then after church tomorrow re-install it on the car.

I'm going to re-use all the old gaskets, they look pretty darn good. I have already ordered a full set of new gaskets but they won't arrive until Wednesday or Thursday. This way, if the repair did NOT work then I haven't wasted a set of new gaskets in the process. If I have to order a new EGR valve after all, then I'll also have brand new gaskets already.

If I put it back together and the EGR valve leak is fixed and the old gaskets hold, I'm done! If the valve is fixed but the old gaskets leak then I'll replace the gaskets when the new ones arrive.

I guess I have a plan now.

 

I have basically re-built my BMW from the ground up, and I kept an old Volvo running like a top from 150,000 miles to 220,000 miles when I sold it. I am pretty darn handy when it comes to working on cars. These Jaguars sometimes seem to defy repair. It's like trying to cheer up a depressed person, they don't WANT to feel good.

Ok, heat-of-the-moment pity-party over, back to being an adult now.

So after putting everything back together the old re-used gaskets don't leak! So that's good. At first it appeared that the EGR valve didn't leak either, no change in fuel trims when I sprayed it. But, my fuel trims were just as bad as before, a little worse even. I sprayed the EGR valve again, in the spot it used to leak, with an aggressively concentrated stream of carb cleaner. This time it shot the negative fuel trims to -25. It takes a lot more carb cleaner, but the leak is still there. Perhaps the leak is farther under the valve and the carb cleaner had to flow down the side? I don't know. I thought I sealed every crevice on that darn thing!

I will perform a smoke test again in a little while. I'm going to relax in the A/C for a while first. It's 95 F and humid outside and my garage is not air conditioned.

 

Smoke test reveals absolutely nothing. I completely closed off the system to get maximum pressure and found no leaks anywhere. The EGR valve had been pouring smoke before I sealed it, now it doesn't appear to leak at ALL. But, my long term fuel trims are now between +10 and +20 !

After the smoke test I started the engine and sprayed everywhere, with starting fluid. I did this very carefully of course. When spraying in the area of the EGR valve, or anywhere else for that matter, I could not make the fuel trims change. About two times out of 100 (used a whole can) I got wildly negative (-25) trim. It was around the EGR valve. But I could do it over and over again and not duplicate it. I am very perplexed. My findings don't point to any diagnosis. I'm afraid I've worked all afternoon and accomplished nothing.

 

I have had my 02 XJR for about two years. I am 90% confident that the car has the same issue as yours when I bought it, but it is possible it came later. It has a tiny stumble when idling at cold, and a very slight stumble at idle when warm (a bit more in neutral than when in Drive). I too thought it was an air leak, and only using carb cleaner tests found the only slight raise in idle when spraying near the egr valve (I too had removed the TB and EGR and cleaned both and replaced with new gaskets.) LT fuel somewhat positive at about +7-10. I put in a new partial load breather (because I broke it when replacing the valve cover). The only wild trim changes came when the MaF connector started to loose connection, which I brought up earlier.

Acceleration, power, and response is great (you mention yours was also fine), especially considering it is over 100k. Mileage is 13.5 on average (city and occasional d-bag highway driving, mostly)

It still does it, but I have put 7k since I noticed it, and it has not gotten worse. I have shown it to 3 mechanics, and none thought it was a problem. My dad who was a merc mechanic for 40+ years didn't notice until I mentioned it.

I guess the point is maybe..don't worry about it? Maybe yours is worse than mine...but I figure if it gets no worse, and there is not a performance or mileage impact, it is not a problem worth dealing with until it gets worse. I got into another XJR (99), and it did not do it, but again...I am not sure it's a problem worth fretting about.

Fyi, like yours,when I cleaned the TB and EGR the bolts were quite loose around there, but are now right. Maybe when I need to remove the supercharger if the pipes under it leak, I will renew everything down there, but for now so don't see a problem.

Fyi, just in case anyone asks, it has new spark plugs, tensioners are good, etc.

 

Fyi, I was reponding to your earlier post when it had not gotten worse in your last post. Not sure what to say at the stage you are at now...sorry!