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Discussion Starter · #1 ·
Hey guys.

I have an 87' MR2 with a 4agze swap and i'm having some issues with the amount of smoke it puts out.

It starts fine, but if you let the engine idle for awhile or give it throttle the engine starts to pour out a lot of smoke both from the exhaust, and from where the exhaust manifold meets the engine.

Would it be safe to assume this is likely due to head gasket failure? If it's any help i took off the exhaust manifold and there was a slight build up of oil around the 4th cylinder right where it meets the exhaust manifold.

I plan on doing a compression test some time in the next few days, as soon as i can borrow a compression meter from a friend.

Thanks for the help.
 

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It's never safe to assume that any symptoms are a headgasket until you diagnose and confirm it's the headgasket.

Compression test is a good start.
Also try to figure out if any changes like giving it gas, letting off the gas, decelerating accelerating ect make it better or worse or if it stays pretty much the same all the time.
 

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Discussion Starter · #3 ·
It's never safe to assume that any symptoms are a headgasket until you diagnose and confirm it's the headgasket.

Compression test is a good start.
Also try to figure out if any changes like giving it gas, letting off the gas, decelerating accelerating ect make it better or worse or if it stays pretty much the same all the time.
Right. Well i'll see if i can do some other tests in the meantime.
 

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An oil leak that drips on to any part of the exhaust can cause smoke from the engine bay at the exhaust side. What color is the smoke from the exhaust pipe? Does it vanish (steam) or does it linger (fuel)? Black, white, grey?

How does it run? Is the engine strong?

A compression test would be a good idea. Just be careful interpreting the results. I misdiagnosed a blown head gasket and spent a ton of time doing work that didn't need to be done. Lesson learned here :)
 

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valve cover gasket?
Any work ever been done to the engine? If not all the rubber in the seals is bound to be getting old and dry by now.
Usually on a little 4 cylinder you would know a head gasket right away. It would miss and most likely run very rough.
check coolant for milkshakey-ness check dip stick for the same.
Compression test is always a plus, just be sure to un-plug the injector resistor pack to keep from spraying fuel when testing and also unplug ignitor to keep from sparking.
 

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Discussion Starter · #7 · (Edited)
It's hard to tell but the smoke appears to be grey/white.

The engine takes a 2 or 3 seconds start when i turn the key, but runs well enough to drive. I feel like it stutters a bit on acceleration though.

I recently rebuilt the distributor, but other than that and an oil change, i haven't done any other maintenance to the car. I'm not the first or second owner though so i wouldn't be too surprised if the problem was caused by the previous owner's neglect. It's not a surprise, i bought the car knowing i'd have to do work on it. I've done less than 500 miles on the car since i bought it.
 

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Are you having to top off oil and/or coolant?

If the visible vapors from the exhaust is dissipating quickly and is white, that is steam and indicates a head gasket issue. If it lingers in the air until it drifts away, is dark color, leaves black residue around the bumper, and stinks like burning oil, then it's oil and indicates head gasket and/or piston problems. Either way, cylinder pressure test will be useful. And either way you are pulling your head if the test results are bad.
 

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Discussion Starter · #9 · (Edited)
Compression was around 130 on the 1st and 4th cylinder, and around 140 on the 2nd and 3rd.
There didn't appear to be any loss of pressure during a leak down test.

Furthermore, i removed the valve cover and there didn't appear to be any signs of mechanical wear off of a quick glance. Although i did notice that the spark plug around the 4th cylinder had a good amount of oil on it.

Also sorry guys, i changed my mind. it's blueish smoke.

I haven't driven it a whole bunch since i last changed the oil (less than 10 miles) so i haven't had to top off any coolant yet.
 

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With the compression and leak down tests looking ok and the oil on the spark plug threads and the oil at the exhaust manifold #4, it could ether be #4 oil ring or intake valve guide seals. My guess would be the oil ring. My car uses a little oil, I replaced the valve guide seals because it was easier than a ring job but it made no difference to the oil consumption.
In my car the #4 spark plug seems to get the most oil on the threads as well.
 

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Discussion Starter · #12 ·
this is a great site...it might help....have a look...

http://www.pbase.com/aw11mr2/mki_engine&view=tree
Super convenient. Thank you!

With the compression and leak down tests looking ok and the oil on the spark plug threads and the oil at the exhaust manifold #4, it could ether be #4 oil ring or intake valve guide seals. My guess would be the oil ring. My car uses a little oil, I replaced the valve guide seals because it was easier than a ring job but it made no difference to the oil consumption.
In my car the #4 spark plug seems to get the most oil on the threads as well.
I was thinking the same thing at this point. I'll see if i can replace my valve guide seals before doing something as big as replacing the oil ring.

Thank you guys for all the input.
 

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Super convenient. Thank you!


I was thinking the same thing at this point. I'll see if i can replace my valve guide seals before doing something as big as replacing the oil ring.

Thank you guys for all the input.
You would be better off diagnosing the problem first.
If you end up needing to go in to do rings doing the valve seals will be much easier with the motor out of the car.

To do valve seals in the car it is very hard and a little risky to do it with the head on. On the other hand if you pull the head and replace the seals and then find your rings are the culprit you will have already done 60% the work to pull the motor and do the rebuild then put it back together and then need to do it all over again.
90% of the time it is cheaper, easier and faster to diagnose it first then address the problem.
 

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How much oil is it eating?
Any idea about how many miles/kilometers are on this thing?
Don't bother with stem seals. Sure they'll cure a little startup puff of smoke, but they never have and never will cure any oil consumption or heavy smoke problem.
External engine smoke from the head & ex manifold area is from a leak, same with the plug threads. Fix the cam cover gasket/s!!!!


Would it be safe to assume this is likely due to head gasket failure?
Your question shows a real lack of basic knowledge, so best bet, just drive it.
 
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