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Resolved Smoke after rebuild block

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AWD-Tony

Proven Member
6,801
3,735
Sep 11, 2017
Cincinnati, Ohio
I recent built my bottom end and installed everything. It would start smoking in about 20 seconds from cold start. Today I removed my manifold to see if it’s one cylinder or more and I don’t see any smoke. There’s ZERO shaft play and I even pulled my bov off while it’s running/smoking and didn’t see/feel anything so it’s not the cold side.

Compression is 110 across the board
Spark plugs look fine
Picking up leak down tester today at 3pm
Pressurized coolant to 15psi and it would drop very slowly. 1-2psi in a few hours.
There are signed of coolant on the oil cap

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Smoke does get thicker

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95% sure you have a cylinder head to block sealing issue. Likely culprits include: bad machining on head, bad machining on block, bad head gasket, not enough bolt preload to seal up the head.

Good luck with it.
 
Head was resurfaced last year and when I brought it to the machine shop this time, he told me it’s straight. Originally installed mls and after the smoke, I changed to oem composite with same results. L19 torqued to 105ftlbs in 3 steps. Wouldn’t it smoke with the manifold off if it was sealing issue?
 
I literally just dealt with this after doing a head gasket and valve job, my torque wrench only goes to 80 ftlb so that's what I originally torqued my arp studs. I went back with a long breaker bar and applied a 1/4 turn more to each head stud and the smoke had stopped. But sounds like you already retorqued yours and used a good value.
 
Not sure what you're saying about the manifold, but everything you are sharing points to a textbook case of a block to head sealing issue. Low compression, white smoke, fluid mixture in your coolant between oil and coolant, a leaking coolant system... that's all classic head to block sealing stuff.

I like machinists, but when I have a problem like this I verify what they say. Check the head yourself, check the deck of the block yourself too. Ensure you have a new, perfectly good head gasket, make sure you're getting the head fastener preload you think you're getting. If it's not one of those things, I'd still peg that sealing interface as the problem but might think about a different route cause like surface finish values meant for the head gasket type you're using, or something maybe stranger than that.
 
@iceguru1114 I’m not disagreeing with what you’re saying. My question was that if in fact it was head gasket or mating surface issues, wouldn’t I see it smoking even with the manifold off? I double checked the torque spec and none budged at 105ftlbs. Just did a leak down test and they’re all around 10% with nothing coming out of the coolant system.

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Your compression Is low , based on the fact that your compression doesn’t vary cylinder to cylinder I would say you might have a ring sealing issue. How was the lower end rebuilt ? Also ... was the head rebuild? New valves seals and lapping ?
 
Your compression Is low , based on the fact that your compression doesn’t vary cylinder to cylinder I would say you might have a ring sealing issue. How was the lower end rebuilt ? Also ... was the head rebuild? New valves seals and lapping ?

Top ring .022 and .024 for second ring. Oil rings was .020 iirc. I did the head last year. Replaced 3 intake valves as they were out of round and all exhaust valves w used evo 8. Lapped all valves.

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Is your turbo water cooled? Another possible suspect. Are you checking that compression cold or hot?

Yes water cooled 68hta. I’m thinking the smoke is from the turbo also but I’m so stumped right now. Those numbers are right after the idle video w manifold off. Ran for only a minute

I switched the drain since it was almost touching my dump. I thought it was ok but do you think this is backing up the drain? It’s fed from OFH

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Only oil cap shows signs of an issue. Oil looks fine

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Im of the opinion go drive it. I'm doubting anything is seated and the tests are premature.

Guess it won’t hurt. I’ll do that and report back. Pray to the dsm Gods for me
 
Guess it won’t hurt. I’ll do that and report back. Pray to the dsm Gods for me
To be completely honest ... I don’t think driving it will change anything. Something is wrong, clearly. The motor should have compression that low on a rebuilt lower end .The past 5 motors I’ve built have all had Atleast 150+ compression On cold motors that weren’t broken in. The lower end was brought to a machinist ?
 
To be completely honest ... I don’t think driving it will change anything. Something is wrong, clearly. The motor should have compression that low on a rebuilt lower end .The past 5 motors I’ve built have all had Atleast 150+ compression On cold motors that weren’t broken in. The lower end was brought to a machinist ?

Yes. They did all the machine work and I assembled it. Honestly might be the head. When I got the car, it was 120, 90, 90, 100 iirc. Replacing the valves brought it up 2&3 to 100 or 110. Probably can use a valve job
 
To be completely honest ... I don’t think driving it will change anything. Something is wrong, clearly. The motor should have compression that low on a rebuilt lower end .The past 5 motors I’ve built have all had Atleast 150+ compression On cold motors that weren’t broken in. The lower end was brought to a machinist ?
You do have a point. Id like to know the manner of the test conduction etc. Whats the specs etc.
 
Yes. They did all the machine work and I assembled it. Honestly might be the head. When I got the car, it was 120, 90, 90, 100 iirc. Replacing the valves brought it up 2&3 to 100 or 110. Probably can use a valve job
So the motor had the same compression as it did prior to rebuilding it. The head you used, you had it decked and through new valves in it and lapped them in ? I’d have the head pressure tested and if it passes do a valve job for sure. Seems like the problem carried through to the new engine
 
I agree. If after rebuild compression stayed the same i would be suspicious. I will add rings "could" still use some to fully seal. What cams are in it? They can change cranking compression quite a bit. My 10:1 motor with multiple different cams and adjustment on the gears has swung as much as 40-50psi on compression test.
 
So the motor had the same compression as it did prior to rebuilding it. The head you used, you had it decked and through new valves in it and lapped them in ? I’d have the head pressure tested and if it passes do a valve job for sure. Seems like the problem carried through to the new engine

Valves I put in last year weren’t new. When I did the water test, it seeped a little from each cylinder. It wasn’t terrible so I just rolled with it. I didn’t want to spend the money at the at that time.

But what I’m most concerned about now is the smoke and oil cap showing what seems to be moisture getting through somewhere. It didn’t do this before. And wouldn’t I see smoke when idling without the exhaust manifold?

I agree. If after rebuild compression stayed the same i would be suspicious. I will add rings "could" still use some to fully seal. What cams are in it? They can change cranking compression quite a bit. My 10:1 motor with multiple different cams and adjustment on the gears has swung as much as 40-50psi on compression test.

Kelford 272. But compression was same before I replaced those when it had stock cams
 
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Tony how long did the motor sit with fresh oil before the very first startup? So when you assembled everything together and dropped it in the bay, how long did you wait?

To me, judging by everything else you've gone over and said, it might quite possibly be a case of condensate and condensation. Even if your garage isn't heated, due to the big temp differences ( I just checked your weather in Cincinnati), from the chilly night to warm afternoon temp swings, it's enough to cause the oil inside the motor to start accumulating condensate (quite visible on your oil cap). Also, due to the same temp swings, you'd also be getting lots of water trapped within the exhaust system, and as soon as the hot gases start passing through it, it would make the water evaporate instantly and thus you get lots of white smoke for awhile until both the system and gases reach a high enough temperature to be completely dry and hot. I recently had the exact same issues with white smoke and condensation under the oil cap on my brother's new 8G Galant VR-4 and it was a matter of too much water content in the oil and very broad temp differences during the day.

Additionally, I had a quick glance at your oil pressure gauge and it looked mighty high even for a cold start. Have you deleted the balancers?
 
Tony how long did the motor sit with fresh oil before the very first startup? So when you assembled everything together and dropped it in the bay, how long did you wait?

To me, judging by everything else you've gone over and said, it might quite possibly be a case of condensate and condensation. Even if your garage isn't heated, due to the big temp differences ( I just checked your weather in Cincinnati), from the chilly night to warm afternoon temp swings, it's enough to cause the oil inside the motor to start accumulating condensate (quite visible on your oil cap). Also, due to the same temp swings, you'd also be getting lots of water trapped within the exhaust system, and as soon as the hot gases start passing through it, it would make the water evaporate instantly and thus you get lots of white smoke for awhile until both the system and gases reach a high enough temperature to be completely dry and hot. I recently had the exact same issues with white smoke and condensation under the oil cap on my brother's new 8G Galant VR-4 and it was a matter of too much water content in the oil and very broad temp differences during the day.

Additionally, I had a quick glance at your oil pressure gauge and it looked mighty high even for a cold start. Have you deleted the balancers?

Stefan, motor was assembled mid August and I dropped it in 2-3 weeks ago. I added oil the day I started it. Oil pressure gauge shows 80 cold and drops to 16-18 once it’s fully warmed up. Honestly don’t think it’s condensation.

Omg. I think it’s moisture/water in my muffler. What do you think?


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My concern is your compression... that is very very low. Does the motor have forged internals or stock pistons

weisco eagle h beam

Just took it around the block a few times. Only have 2 gallons of fuel and I can’t see sh1t out the windshield. It doesn’t smoke while I’m cruising.
 
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It needs a nice, long drive to get all the pipes real hot and evaporate all the water. Which break-in procedure are you gonna follow? Drive it a bit more and see if it still smokes out the exhaust while stopped and if no water is visible at the tip. I'm still thinking it's just condensation.
 
There’s nothing under the oil cap now which I’m super glad to see. Going to grab some fuel later today or tomorrow and take it for a longer drive. I didn’t want to go too far since there’s a lot I did to the car but think all is good now to hit the road. I will update afterwards. Thanks all for the input!!
 
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