4G63 Galant GTi N/A tailpipe and oil cap smoke. Help.

[DaddyV4G63]

Hello fellow DSM lovers! Asking for your help on this one, I’ve had this “project” car of mine for the past two years and with budget issues I can’t fully pay someone else to fix my Galant GTi (4G63 DOHC 1G) N/A variant of the VR4. It started with a bad timing causing misfires, then it lead to an bent valves, and overheat after the rebuild, after spending much hours and money I’m trying to learn how to DIY the whole project so I can save money from the labor and focus on the parts that are needed by the car.

Sorry for the long intro but here it goes… So after the bent valves incident I took it to the machine shop to be resurfaced and install new valve guide, valve seals and valves after that some cheap backyard mechanic worked on it and didn’t properly time the engine (which caused misfires) while I’m driving the car one day it suddenly overheated probably caused by the misfires and my radiator fans got disconnected.

Then I took it to the more expensive mechanic and timed it properly however there's a new problem arises, excessive smoke coming from the tailpipe and the oil cap valve cover. I’m thinking if whether if it’s the valve seal (which are new) or maybe the oil ring (I tried compression testing all three cylinders showed similar results but cylinder number 1 shows a lower compression). Question is should I just try the valve seal replacement or go full send on the piston ring repair?

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[3gmoneypit]

DaddyV4G63,

Looks like you are taking the crash course in cars. We have all been there, so I am not poking at you. You really need to read and understand what is going on before you do anything.

Let’s start from what you have told us:
You had the head off for the valve job. Did the mechanic comment on how the cylinder walls and piston tops looked? Think carefully, you might have dismissed his comments as being unimportant. Any mechanic who gets a chance to look inside an engine ALWAYS looks at how everything else he/she can see looks. Chipped, burned, or heavy build-up of carbon or burnt oil on the pistons would have been evident. Glazing or scoring of the cylinder walls would also be key observation points.

You talk of excessive smoke…what color? White? Blue? Black? When? When you rev it up? When you let off of it? Smoke from the oil cap? Is your PCV valve functioning? Again what color is the smoke?
A comprehensive compression test can tell much on what is happening inside the engine. Read up on how to do that as well as how many cylinders your car has.

Always try to get as much information as you can before making a diagnosis. Just blindly throwing parts at the car based on guesswork is a sure fire method to waste money.

Oh, by the way, I see you are new here too, welcome!
Cheers,

 

[DSMPT]

some cheap backyard mechanic

the more expensive mechanic

Doesn't really matter if they are cheap or expensive, who you should look for is a person who is very familiar to Mitsubishi 4G series engines. Specifically 4g6 if possible.

 

[DaddyV4G63]

DaddyV4G63,

Looks like you are taking the crash course in cars. We have all been there, so I am not poking at you. You really need to read and understand what is going on before you do anything.

It's been a year now. We fully rebuilt the engine, replaced all the bearings in the crankshaft and the connecting rods, also resleeved the bore cylinder and new piston rings.

My new mechanic just finished last week, now after all of that my engine is now overheating and running poorly. The mechanic was ok but he just isn't really familiar with 4G63, the car was abandoned for about a year, what could be the possible issue?

I'm reading up on the service manual it says it could be the ignition timing (not sure if he got it right but i feel it runs on all 4 cylinders) or the cooling system (which we fixed) aside from those two mentioned are there anything else I could suggest we check? (electrical, running lean, leaks, vacuums or other stuff that might contribute to the engine overheat?)

BTW, thanks for the very informative reply and warm welcome!

 

[3gmoneypit]

DaddyV4G63,
When this rebuild was happening, did you happen to replace the thermostat? Or are you running the same one you had when it was overheating previously? When the rebuild was complete, did you make sure to completely fill the cooling system with new coolant and take the time to “burp” out any trapped air in the engine? Are your fans operating? You had previously said that at one time they were disconnected. How is your water pump? If you can get that overheating under control, you can then tackle the running poorly condition. Even running poorly, you should be able to maintain temperature.
Cheers,