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Should I change the valve stem seals? (fixed) (bad capacitors in ecu)
Hi everyone. I want to get your opinion before I dive into the motor this weekend. I bought this car Sunday and I love these cars. It's my second one I've owned. The guy I bought it from told me it smoked in the morning but when I bought it it wasn't smoking.
I drove it around running good for over an hour, parked it all night and started it the next morning and after idling for a whole minute or two it started smoking and misfiring. The thing I don't understand is if it was the valve seals I would think it would start smoking right away? vs a minute or two later??
Also I tried to drive it around my block 5 times to see if the smoke would go away but it didn't. I'm just really confused about this because I would think if it was the stem seals the smoke would start going away. The smoke doesn't smell sweet like coolant and I'm not losing any coolant. The oil on the dipstick doesn't look milky or anything. I disconnected the vacuum lines that go to the power steering pump and eliminated ps fluid going into the intake as a possibility.
I did a compression test and all the cylinders are 210. It's throwing a 'random misfire' code and its throwing a misfire code in 2,4,6 and 8 cylinders. It's also throwing a P0172 'system too rich' (bank 1) code.
I hear popping sounds while idling coming from the exhaust about mid way down the pipe. like little explosions because too much unburnt fuel is getting in there I guess. Another clue is the car will misfire and smoke but if I turn it off at that point and start it again in the morning it will run fine for a minute before it starts smoking and misfiring again. That is really confusing to me. Let me know what you think. I'd hate to change the stem seals and do all that work for nothing. I appreciate any help. Thanks!
Very nice write up; good to see someone who takes the time to do some logical diagnosis first. I would suggest you pull the plugs to see which cylinders are burning oil. I agree with PD that the rings are not likely the problem since compression is good everywhere. If all the plugs show oil burn, then valve seals, restricted oil return passages in the valve gallery, or PVC sucking raw oil are about the only things left. Make sure that there is no sign of fluid in the vacuum line feeding the brake booster; that smoke could be brake fluid being sucked into the manifold. Very unusual problem for these engines. How many miles?
Thanks everyone. It's a 96 and the motor has 159000 miles.... I disconnected the vacuum lines going from the idle control valve to the intake and drove it around the block a couple of times but it still smoked... I didn't think the PCV valves would cause all this smoke at idle because they're located on the very top of the valve cover. But I'll look into that anyway. Thanks for suggesting that.
bgalarpe.. The ps level has stayed the same and I don't think I've driven it enough since I bought it 5 days ago to notice any engine oil loss. I've checked it a few times and didn't notice any loss.
Since you disconnect the idle control hose and it still smokes...you can add the snake oil the parts store sells or change to a thicker oil. But it looks like you're going to need head work and get the valve seals replaced.
Unlikely to be rings as those would show lowered compression during the testing.
I knew it had to be 95-97 seeing antenna and tail lights... and I cant believe it is the valve stem seals. all on one bank, no way... UNLESS the drain is stopped up on that side and the oil is staying under the valve cover building up until it gets sucked into the engine on that one side...
Ok I just got off work and I'm about to get out there and start working on it. Yeah I'm starting to think the PCV is stuck and causing the oil pressure to build up causing oil to go into the intake. I hope so anyway. It makes sense because you can tell the car has been sitting a while maybe a few years. Needs new wiper blades and the tires are old and dry cracked pretty bad. If it was the stem seals you would think the smoke would go away after driving it. And it only starts to smoke after running good for a whole minute and I'm guessing it's because the oil pressure builds up. I'll be back later to post results.
Damn the new PCV didn't fix it. It started smoking right away and started misfiring a minute later followed by the popping sound coming from the middle of the exhaust. Here's two pics of one spark plug. All 8 plugs pretty much look the same. The smoke smells like nothing but unburnt fuel.
12-18-14, 07:52 PM
Should I change the valve stem seals? (fixed) (bad capacitors in ecu)
