High RPM and smoke after head gasket replaced
Asked by mverona Apr 25, 2014 at 12:16 AM about the 1996 Toyota Celica ST Hatchback
Question type: Maintenance & Repair
Hi, I have a 1995 Toyota Celica (1.8L - 108 cu in) with 250,000 miles. I recently replaced head gasket, valve seals, timing belt, throttle body, water pump and etc. I reseated the valves and there is no leak at all. After initial start, excessive smoke came out even after idling for more than 30 minutes. We figured out the problem and it was wrong connection of coolant supply line. Even we corrected the coolant line, smoke didn't stop. We finally checked the valve seals again, and found out two of them were cracked. So, we replaced them (I replaced the head gasket again with better quality). Now the car is running but smoke is still coming out - not excessively. After driving about 10 minutes, there is no more smoke but whenever I accelerate, thick smoke comes out. Beside smoke, idle is also high. It is about 1,000 at idle. It used to be less than 500. Can anyone suggest me anything to fix those problems? Thank you so much in advance.
22 Answers
Idle issue is possibly a loose vacuum line. What color is the smoke? Blue = oil. White = coolant. Black = unburnt fuel.
was the head checked and resurfaced? Why was the head gasket changed in the first place?
The smoke is kindda black when I accelerate and, at idle it is kinda blue-ish. Yes, I resurfaced the head and check for leaks and all the valves are properly sealed. I replaced head gasket since I was taking the head off and it was original one as far as I know. By the way, I do notice that exhaust manifold is wet with oil. Is it normal or it has to be totally dry? If it is not normal, what could be the problem? Thank you so much in advance!
That's not normal. I would check valve seals again.
I'll check the valve seals again. I'd like to know if it could be piston rings problem. Before I did parts replacement (such as head gasket, valve seals, etc...), there was no smoke at all. My friends are telling me that it could be rings problem. Thank you for your answer!
Do a compression check before you tear it back down. Dry check first and record psi readings. Then do a wet check. (Pour a little motor oil in cylinder right before check) If any of the psi numbers increase considerably with the wet check then you have a ring issue on that cylinder.
Thank you for your prompt reply with suggestion! I have another question. If I were to replace piston rings, should I use standard size? What is your suggestion? Thank you again.
You really need to bore it out to make the cylinders round again. IF the motor has 250,000 miles on it then it will certianly have ovaled them out by now and just replacing them wont do much. However if you want to just change them, standard will have to do. Anything bigger may not fit
Hi again, I have decided not to replace rings as it will be more labor intensive and I'm trying not to spend more on it. I have another question before I take the head off again to replace the valve seals. I've been driving every evening and I do notice that at the beginning there was noticeable amount of smoke (blue-ish) comes out but after a few minutes of driving, no smoke comes out anymore. Is it indication of defective valve seals?
Yes that is a tell tell sign of valve guide seal issues.
I just replaced the valve stem seals with dealer items today. After starting engine, there are two problems. First, I have a very high RPM (more than 2000). So, I replaced TPS but didn't help at all. Second, I noticed that there is an oil leak from exhaust manifold. There is a crack where four exhausts from the head merge into one and it is leaking from there. Initial start even caused the oil sprayed out from the crack but later it dried up after running the engine for a while. So, with this all my bad experience, do you guys think it is the ring problem? Any suggestion? Thanks!
No oil passes thru the exhaust manifold. The oil you saw could have been left over from the seal replacement/issue. The high idle is possibly a vacuum leak issue. I would inspect all vacuum lines. Also inspect pcv valve. Make sure it is closed at idle. Also inspect all intake items that you removed while replacing the head gasket. Did you do the wet and dry compression check? Doing this test will give you insight as to the condition of the rings and cylinder walls.
Before I did the compression test, I saw (through spark plug holes) that there is engine oil on top of all four pistons (in combustion chambers). The compression test came out; 1 and 4 piston = 190 2 and 3 piston = 180 Excessive amount of smoke still comes out! Any suggestions?
if there is alot of oil in the cylinders then the compression reading will be high. If there is lot of oil then they are gonna be really high. Oil should not be in there already. either the head gasket wasn't put on right, the head is warped, the rings are gone, or the valve seals arnt right
Finally, after such a long time, we successfully overhauled my Celica. We ended up replacing all the rings and bearings. Now the car is running in almost perfect condition. I have two minor issues as of now. By the way, we just started the car last night and the idle seems to be a little bit high. It is at about 900 RPM at idle. Is it normal for the engine that has recently overhauled? We adjusted throttle body idle adjustment to its lowest idle position. The second issue is that when I turn on AC, the car runs rougher than it used to be. I installed brand new rear and front engine mounts. What could cause it? Thank you so much in advance.
Idle air control valve not operating properly could cause both issues.
I would also double check the throttle plate. Make sure it closes completely when vehicle is idling or turned off. Also check for any loose or missing vacuum lines.
Thank you for your suggestions! The idle has become normal again after driving for awhile. Now, the idle is completely stable. It is somewhere around 400-500 RPM. The car is still a little bit shaking at the stop lights; other words, car is at stop while gear engaged in drive. I guess it is normal for just overhauled engine. What do you think?
I would just drive it some and see how she does. Glad you got it going. Drive safe
Hey dandyoun I have a couple questions on my 04 civic and it seems like u know a lot about cars
CHARANDEEP answered 6 years ago
hi my celica was not driven for a year was slight white smoke when accelerating changed oil and filter it has reduced alot but still little left noticed a slight gap in front down pipe to cat and cat to mid pipe could that be the reason