Basic backstory- I haven't been driving (or updating) my MR2 thread much because I've been busy replacing and upgrading the interior- but each week I've been starting it and running it for a good ~20 minutes or so to keep running gas and oil through it. 3-4 months ago it began running a little rougher than usual, and with ~30 year old injectors I decided to replace them with remanufactured ones. For a month she ran better and stronger than before (not having your pintile caps be full of cracks will do that), but after April she took an absolute nosedive; whereas before fresh gas made her run fine, now the car can't hold idle whatsoever and starting her is getting more and more difficult. When I drive her, she herks and jerks horribly especially when the T-VIS opens at 4K RPM. I searched for possible vacuum leaks/errors and fixed a few, and also repaired some holes in my intake, but these have had little effect. After testing by yanking plugs and finding that the 3rd cylinder is making the most power (in fact, the engine won't run without it) I yanked the plugs to see and...
Cylinder 1. That schmutz you see on the wrench? It seriously looks like someone vomited into my spark valley. That liquid is partially gas, and some even flecked out when the plug was pulled- this plug really smelled.
Cylinder 2. More gas smell but not as serious.
Cylinder 3. No wonder the car can't start without this one.
Cylinder 4. Scaly around this plug.
And with the Valley cover off. Spark plug 1 is nearest to the picture. The rubber gasket was old, but I couldn't see any obvious ways for water to get inside especially since the hood's undamaged and the car has been under a tarpaulin garage for over a year. I don't immediately see any cracks in the head.
I left the valley uncovered in the garage for a couple of days to dry, and I'm getting newer plugs to replace these older, not-reccomended ones though I'm not sure how much help that will be. We're also building a leak-down tester to check the general health- but to be honest, I'm at a loss for what next to do. Any recommendations?
First off stop starting it and not driving it. Put stabil in the fuel if you want but not needed if you are going to get it on the road in less than a year. Put some ATF in the cylinders and turn it over by hand then put the plugs back in it and don't mess with it until you are going to drive it.
Your gunk in the valley looks like the coating that is on the valve covers has somehow washed down into the valley. Maybe it has flaked off and then the heat melted it? Have you put thinner or carb cleaner on them trying to clean the valve cover and or the valley? I would clean up the valley with some Dawn and hot water and a scrub brush (pressure washer would be better) I would put new gaskets in the valve covers.
Valve cover gaskets leaked and filled the plug area with crap. It happens. Also looks like the plugs might not be the correct length. Use whatever you like and clean up the outer stuff, soak the combustion chamber and then screw in some cheap NEW plugs. Run it for a while then do a compression check.
_
HalfDork
6/27/19 12:27 p.m.
I’m gonna call head gasket, coupled with the lack of proper warm ups after starting. This would mean that gunk from the coolant and oil mixing would get on the plugs but not burn off properly
dean1484 said:
First off stop starting it and not driving it. Put stabil in the fuel if you want but not needed if you are going to get it on the road in less than a year. Put some ATF in the cylinders and turn it over by hand then put the plugs back in it and don't mess with it until you are going to drive it.
Your gunk in the valley looks like the coating that is on the valve covers has somehow washed down into the valley. Maybe it has flaked off and then the heat melted it? Have you put thinner or carb cleaner on them trying to clean the valve cover and or the valley? I would clean up the valley with some Dawn and hot water and a scrub brush (pressure washer would be better) I would put new gaskets in the valve covers.
I screwed up my description- I can drive it, just what kept me from doing so was my seats wernt bolted in. They're in now.
As far as I know, I have never tried to really clean any of the gunk off the valley cover at all. Id had been pressure washed in the past, but that was years ago when I first got the car.
Missed it the first time but these are very picky about the proper plugs. Get new correct plus for it before you start trying to diagnose anything.
Have you done a compression test lately?
porschenut said:
Valve cover gaskets leaked and filled the plug area with crap. It happens. Also looks like the plugs might not be the correct length. Use whatever you like and clean up the outer stuff, soak the combustion chamber and then screw in some cheap NEW plugs. Run it for a while then do a compression check.
Soak the combustion chamber? I don't understand- you mean put denatured alcohol or something into the cylinder?
We use to have to re-ring our MR2's after about 25-30 hours of track time.
_ said:
I’m gonna call head gasket, coupled with the lack of proper warm ups after starting. This would mean that gunk from the coolant and oil mixing would get on the plugs but not burn off properly
That's my concern too- though it was running well enough to be driven to the next town ~5 miles away in March. Could the head gasket steadily 'let go' over that timeframe?
In reply to dean1484 :
Yeah, I have to order the correct NGKs and I have now. The last time a compression test was done was over a couple of years ago when I could daily the car. That was before I decided to replace and improve the interior which lead to it being in a non-driving state for over a year.
porschenut said:
Valve cover gaskets leaked and filled the plug area with crap. It happens. Also looks like the plugs might not be the correct length. Use whatever you like and clean up the outer stuff, soak the combustion chamber and then screw in some cheap NEW plugs. Run it for a while then do a compression check.
_ said:
I’m gonna call head gasket, coupled with the lack of proper warm ups after starting. This would mean that gunk from the coolant and oil mixing would get on the plugs but not burn off properly
These, although I'm not sure soaking the combustion chamber is necessary, WD40, ATF, or MMO would be good fluids to use for that if you want to. As for "maintenance engine runs," do it right or eliminate it. Always make sure the engine gets to full operating temperature before shutting it down, maybe give it some revs before you do. Or if it's just to top up the battery, disconnect it or use a trickle charger instead.
In reply to GameboyRMH :
I have it trickle charged, and my "maintenance runs" would be a ~20 minute heat cycle- I'd typically drive it around my development to get a few miles.
In reply to GIRTHQUAKE :
That doesn’t sound like enough...maybe to get the coolant up to temp, but not the oil; if you are going to start and run a car that sits a lot, you want the oil to reach full operating temp (~200 degrees F) to evaporate all of the residual moisture/condensation out.
Idling and stop & go does not bring oil up to temp very quickly, every car is a little different but in my experience to get there in 20 minutes you would need to spend some time on the freeway doing 2-3k RPM under continuous load. This will also be good for cleaning out the crap deposits in your combustion chambers.
