I looked at a black 89' turbo for sale today

[chris89]

I'm more experienced with the 7m-ge but this supra had the 7m-gte engine. There were a few problems with the engine operation though it is a lower milage jdm engine. I think it may have a boost leak somewhere since it pulled nice under 4,000rpm but after 4,000rpm it totally dropped off almost completely. What are the most common leak points? Yes i have been reading the tsrm . Anyway what's a list of things that i should have looked over on the engine? The turbo had a little oil residue on it. It also had a Manual Boost controller. There was 174k on the black targa 5spd body. No rust. Faded paint on hood bumper and targa. Interior was in good condition, it was beige cloth.

thanks

 

[ForcedTorque]

The intercooler pipe coming off the turbo is the most common place I believe. You may have to take it off and flex it to see cracks. You can get boost leaks all over the intake and intercooler piping. Check the small coupler at the throttle body. Intake manifold gaskets can also be the culprit. And, the bolts on the exhaust manifold have been known to back out or strip. Be sure that the turbo itself is good and tight.

Another thought is, you could have been hitting fuel cut if the car has a boost controller. What type boost gauge is it using? If stock, it won't be accurate with the MBC. And, if it has an aftermarket BOV, is it recirculated or does it vent to the atmosphere?

 

[black89t]

can't go wrong with a black 89 supra turbo. best looking choice to me.

to solve the boost leak problem. i would just take off all the stock intercooler pipes and make sure there aren't any rips or bad cracks. then i would clean the mating surface on both parts which ever they might be and tighten them down. make sure not to go to tight though because it will cut the hose.

other spots are 3000 pipe to throttle body. and the accordian hose. goes from afm to the turbo.

 

[antman]

Do a compression test and check the codes. If the comp. test checks out then I would consider it further. Good luck.

 

[ForcedTorque]

^Good advise right there. You always have SM to lean on for help

 

[black89t]

oh crap. i read it like he already bought the car. my bad.

 

[NeatOman]

You should be fine with just a compression test, but if you want to get anal! It takes a week to do a oil analysis, if you really want to see the engines condition.

You could also ask to tare apart the oil filter to see if you could find any metal.

 

[chris89]

The intercooler pipe coming off the turbo is the most common place I believe. You may have to take it off and flex it to see cracks. You can get boost leaks all over the intake and intercooler piping. Check the small coupler at the throttle body. Intake manifold gaskets can also be the culprit. And, the bolts on the exhaust manifold have been known to back out or strip. Be sure that the turbo itself is good and tight.

Another thought is, you could have been hitting fuel cut if the car has a boost controller. What type boost gauge is it using? If stock, it won't be accurate with the MBC. And, if it has an aftermarket BOV, is it recirculated or does it vent to the atmosphere?

It had an aftermarket boost gauge in place of the stock in the dash. The aftermarket blow off valve vented to atomsphere i believe. It's been lowered too and he said it's been dropped 3"... I could hardly see the springs from looking thru the wheel well but i barely caught a glimpse of what looked like a rusty stock spring. Which tells me it may have just had cut springs and possibly stock struts? I'de have to put it on a lift to really identify the springs/ struts assembly. That could also connect the dots on the rather rough slightly bouncy ride. The camber was off in the rear as well causing inner tire wear meaning positive camber?

thanks