Exhaust leak behind engine?
 

i got a problem with an exhaut leak in my 7mgte. the leak is coming from the back of the engine, by the firewall. not sure what it could be? i can't see nor when cold feel where its coming from.

if its the egr or related components, i was thinking of getting a block-off plate and geting rid of the egr. i've read that's not the best idea because that cools combustion temp. but it might be a cheaper fix.

If it is the exhaust leaking it could be the egr maybe. If it is the egr cooler though it is not fixable without removing the head first. It also could be that you have one or two stripped out exhaust manifold studs causing a leak.

Not true you can replace the egr cooler with a gasket with the engine still in the car. it will probably be tricky to get the gasket material scraped off the head but it can be done. But it does sound lke the egr cooler is leaking. If you want to do block off plates its recommended that you get a jdm ecu. otherwise you might as well get a new egr cooler gasket.

I have an exhaust leak in the same location "about" were the man is speaking.

stripped exhaust bolt is the most likely suspect, Unless you did not rebuild your head gasket in the last year. good way to rule that out. did you take off your exhaust manifold?

I have the same problem. I removed the seal on the rear of the hood to draw more air from underhood and keep the engine cooler. But when i'm idleing I get exhaust gasses in the cabin. I'm pretty sure it is coming from the engine bay as before i removed the rear rubber seal I didn't have the exhaust in the cabin.

I'm putting on a flex-a-lite 410 fan, uderdrive crank pully, and front strut tower brace as well as a dyno and tune over the next couple of days and will have Splitfire Auto look into the exhaust problem as well.

I'll report back soon.

i just heat wrapped my manifold, and my manifold gasket was barly there...
i would start with where manifold reaches exhaust.
also its only like a 1.5$ / foot of the vacuum lines if you think its egr, just buy 10 ft and start 1 vacuum line at a time i replaced every line on mine just because i could for under 30 dollers (it took about 26 feet for my 84 5m-ge)

also i have seen these manifolds crack, check for cracks and make sure the heat shield studs are all tight, because they go strait through to the inside of the manifold

Here is a good link about the exh man. studs that i've found as well as some other good info for anyone interested
http://cjsupra.kendra.com/Helicoil.html

just pull a small vac line and run some atf into it look for the smoke and you've found your leak and gotten a slight decarbon or you could buy some seafoam and do it and get a full decarbon

sat i blew a freeze out plug from the block and to replace it i had to take the exhaust manifold out. every bolt that came out came out wit threads and the rear 4 bolts where loose cause they where stripped. also from the head and gasket i can tell i had a major exhaust leak from cylinder 4 to 6. sucks now time to heli-coil. i will let you guys know how it comes out after repairs.

Supra engine woes
 

The exhaust leak has been fixed.

I had the car in the shop for a week and after $800 it runs poorer than when it went in.

I'm questioning the under drive pulley and the fan. When the fan is set too low, it runs after shut off and kills the battery. If it is set too high, the engine temp fluctuates - and when it gets hot, the a/c doesn't blow cold. As soon as the temp goes back down, cold a/c again. Can anyone explain this?
Maybe the under drive pulley is turning the water pump too slow? Electric water pump?

Also the car has a real problem getting boost and will not go above 7 or 8 lbs. and really struggles to get to higher revs (above 5000 rpm).

At idle it has a stumble about every 5 seconds or so and that stays as the revs climb.

The mechanics checked the entire system for leaks, replaced the waste gate, replaced the plugs (that were only a month old - what could kill the plugs so quick?) and could not get the boost to go up.

There is also a pretty good resonance at 3400 rpm that is new and feels very weak. It sounds and feels like drive line not exhaust.

When I brought the car in i could get 12-14lbs boost no problem. I just wanted it fine tuned.

when i left the shop he said maybe i need a new turbo so i agreed to purchase a set up, inter cooler and all, and have him install it.

On the way home after getting gas the battery was dead. Fans kept running.

I called him and he suggested that maybe i need a new motor.

I really need some sound advice here. I just want the car to run at it's best and I'm having a hard time getting that done.

I had the same problem on my 7mgte turns out the manifold studs were all hand tight the maifold brace was not attatched and the gasket was destroyed ad the manifold was cracked. Check all of this ad alll your vacume lines they all make a big difference

wow. sound advice would be to get a new mechanic. sounds like hes taking you for a drive. you went in for an exhaust leak and came out with 2k in parts.. now hes suggesting more. sounds like someone is trying to cover up some foul work. more information on this please.

Under Drive Pulley
 

I need to clarify that it was my under drive pulley that was installed at my request so the shop cannot be blamed for that. Another mechanic suggested that many Japanese cars have their crank pulleys balanced with the crank so that is likely why the new pulley didn't work.
But it really ran like shit!
I highly recommend not changing the crank pulley unless you have it balanced with the crank - just say NO!

The boost still climbs slowly and won't go above 7 or 8 lbs. I'm thinking maybe the cat is plugged, although it is only a month old, (but so were the plugs and they had to be replaced).

Back to Split Fire today to check this out and hopefully finally have the car tuned on the Dyno. I have a time attack at Mosport this Saturday.

Exhaust leak
 

I need to mention as well that Split Fire fixed my under-hood exhaust leak.
I will ask him today what the problem actually was.

Over Boost
 

Just got back from the shop - 3 hr highway drive.
She's back baby!!!
It was the cat. Cleaned it out an voila - all the boost i can stand.
Only problem is for some reason my under hood manual boost controller will not lower the boost so i have full boost all the time - it will go to 15 - 17 and then cuts out. I'm getting a anti boost cut unit or what ever you call it on Monday but that doesn't help me this Saturday at the time attack at Mosport.

Does anyone know of a trick of some kind to lower the boost short term??? I cannot floor the gas because it hits the cut off. It's quite tricky to get maximum boost while staying just under the cut off point.
If anyone could help with this it would be really appriciated.

And the exhaust leak was a loose bolt on the downpipe.