SuperSevenRacer

Hi Guys, I am suffering from a very odd problem with my '97 V8TT. I just had a full engine rebuild performed due to a cracked cylinder head that was causing an overheat condition, but now after breaking in the engine, the coolant temperature spikes to full overheat within seconds of boosting the car hard in 2nd and 3rd gear as the cooling system overpressurizes and pukes. I can drive the vehicle normally with no overheating condition or overpressurization of the cooling system. My car is modified with air/water intercoolers, ball-bearing turbos, large capacity radiator, etc. Currently pushing around 12-14psi of boost. My shop and I have checked every imaginable component of the cooling system and all is correct. Water pump is brand new, thermostat, etc, etc. We even obtained another V8TT for comparison purposes and both cars are set-up identically so there are no issues with coolant flow, coolant hose routing, etc. What is interesting is that the coolant temperature drops very rapidly after the car runs hot and overpressurizes. If we shut the car off, the temperature will drop back to normal within 3-5mins of sitting. We replaced the cylinder liners and are currently utilizing JAE's custom head gaskets as the OE units are no longer available. When we sniff the coolant for hydrocarbons, there are no hydrocarbons present. The only thing my shop and I can conclude is that we may be dealing with a head gasket problem. We are figuring that the gasket may not be designed correctly and is not sealing against the liner sleeves well enough so when the combustion increases under boost, the gasket is separating enough from the top of the liner to allow combustion to escape into the coolant which is causing the rapid overheat and overpressurization condition. The car performs flawlessly otherwise. Curious to know if anyone else has suffered from this issue after rebuilding their motor? It has become quite a pain for both myself and my shop! Any input is greatly welcomed from all you experts! :-) Best Regards, Matthew

Thanks for your response! After removing the cat's I now see what you are talking about. I was able to find the 3-bolt flange without a problem; however, it was ball/socket joint on the other end of the cat that posed a problem. Instead of having the muffler shop build a set of pipes, I ended up buying a set of direct bolt-in Larini pipes. In the long run they will be well worth the price, plus they look fantastic! Best Regards.

Hey Guys, Finally decided to have a set of test pipes installed on my car. I'm have custom pipes built so that I can easily interchange the cats with the test pipes when the car needs to be smogged. I don't want to have to cut and reweld things everytime I need to switch. So with that being said, I need to locate two downpipe flanges so that the muffler shop has something to weld to instead of the exhaust housing. I found out that there is a significant difference between the T3 downpipe flange and the T25 flange. Does anyone know if the flange is something special or will a typical 3-bolt 2.5" header flange work? Please see provided Ebay auction. I still have the exhaust on the car so I do not have the capability of comparing the flange on the car with the flange that I think will work. Any quick help would be greatly appreciated, as I'm trying to have the work done tomorrow! Best Regards. http://cgi.ebay.com/ebaymotors/2-2-5-Exhau...98349QQtcZphoto

Thanks for the responses guys, and yes Gonzalo, this is Payman's car. Havent had too much time to drive it yet due to poor weather conditions, but the car is exceptionally clean and very strong. So I've decided I'm going to go ahead and have a set of test pipes fitted. I'll have the rear 02 sensors spaced far away from the front 02's and see how long it takes the car to throw a CEL. If it does, which Im assuming it will, I'll have the shop use the spacers for the rear 02's. Hopefully that will do the trick, but if not, I'll look to the cat simulators as the next option. I'll keep you posted! Happy Holidays as well....

Hey Guys- I've recently acquired a US spec 2003.5 Final Edition Esprit and have a few questions about removing the cats. I have already used the search function and found minimal amounts of information that was helpful, and am hopeful that someone with a US spec car can chime in! The previous Esprit I owned, a '98, had the Lotus Red Race ECU installed which only pulled readings from the front 02 sensors which allowed the car to run fine without the cats. My current car's ECU has the Sport 350 or High Torque flash and I'm lead to believe looks to the secondary 02 sensors for readings as well. I'd like to remove the cat's and am OK with a CEL coming on occasionally; however, I'm concerned that the ecu will limit boost if it's sensing irregular readings from the secondary 02's. Obviously one way to figure this out is to just have the test pipes installed and see what the effect is, but Im curious if there is anyone who has de-catted a US car and didn't have the red race ecu? I'm also curious if anyone has had experience with cat simulators? They seem to work fine for many American and Import vehicles; however, I'd be weary of installing them on an Esprit. Looking forward to any input!