hey.. So been pretty good with the mav. Made the mistake of putting 5w-30 in it when it was super cold and then driving to georgia. (yeaaa... i know ) Started smoking the car cheech n chong style on me and the oil light would light up here n there. It shot a bunch of oil out of the filler cap too :16suspect Changed the oil to 10w-30 n still have a problem. Smoking isn't so bad now with a new pvc and a cleaning of the oil filler cap, but it's still running kinda rough and puffing some smoke out of the oil filler cap. Ran it at idle with a bunch of seafoam in the crankcase for a few hours starting with the idle high so it wouldn't stall and slowly backing it down. Thought I'd drop the oil pan, clean the screen and reverse flush my pump, but just found out what a pain that is to do in the driveway.. Thinkin maybe could be a valve seal? Don't know how to tell if they are bad.. Any thoughts or things to try before the arduous task of trying to drop the oil pan if I don't need to? My second car is currently off the road with a mysterious computer problem so I'm stranded til something's fixed.. Thnx. Hope all's been well!
sounds like you might have a more serious problem like piston or rings running 5-30 wouldn't cause this. if an eng. is in proper workin order 5-30 in cold weather would be fine
I wouldn't think 5W 30 would cause any oil problems either. Where was the smoke coming from the trail pipe or the oil filler breather? Did this problem start only after changing the oil to 5W30? No smoking problems at all before adding the 5w30? Was it a quality oil or a store brand oil? Years ago when I was broke, oh wait I am still broke but I changed the oil in a little rear engine riding mower and I used a cheap engine oil that was recycled. That mower smoked like crazy until I changed the oil and put decent oil in it. lol clint
It didn't smoke at all before changing to 5w-30. No problems at all. I was proud . Within 30 miles of changing the oil I had a problem, consequently when I went down the mountain into warmer weather too.. idk what matters. Doesn't smoke out of the tailpipe, just the oil filler cap. When I see smoke behind the car it's oil shooting out the filler cap and burning on the engine. This especially happens when at high rpms.. My air cleaner got shot with oil so I removed it and turned the spout towards the hood and I can see where it's getting shot with oil. It's not overfilled or anything either. The smoke out of the filler cap happens whenever I accelerate. It was smoking out of the filler cap constantly until I did the adjustments I listed above. Yea, it's just advanced auto parts oil. but that's all i've ever used on this car... I'm perplexed. Gonna drive it tonight and see if it blows up. I NEED to get out of my house haha Thanx for the input guys! I hope it's not a more serious problem.. but started searching ol' craigslist for a 302 just in case
Do a compression or leakdown test before pulling anything apart. Sounds like something gave up the ghost. Was the oil a synthetic blend...I have seen the blended oils cause smoke issues along with oil loss/consumption.
Sounds like too much pressure in the case. That is usually compression escaping passed the rings/pistons. The valve seals will not cause oil coming from the dipstick or cap. They just cause smoking when the oil is too light or on startup, after leaking trace amounts into the cylinder overnight.
Agree. I have seen synthetic oils AND things like Marvel Mystery unseat the rings. Seafoam may have the same effect??? The 5w30 "mistake" may not have had anything to do with it. Could have just been destined to give up on you during your road trip... or maybe the 5w30 made it give up a week sooner than it would have.
It's not a likely candidate for 'blowing up'. Rings are not usually a sudden failure thing, like bearings for example. It could die a slow lingering death over the next year or more with bad rings.
Thnx guys! I'll research leakdown n compression testing in the morning. Finally warm here! Naw, it's not synthetic (I'm too cheap for that haha) The oil level is correct, even running it at the bottom end of correct just to be str8.. Didn't seafoam it until after having the problem. Good to know it won't blow up! Gotta get to work this week, I was stressin'! I'll see how it does tonight. Not expecting much lol. Thnx again!
Compression test results: cylinder #1: ~80psi, #2: ~35psi, #3: ~haven't done yet cuz I'm guessing I'm screwed anyway.. worth doing the other ones? guessing this means I have a bad ring and it's time to go 302.. nothing else can cause this right? -Engine was at operating temperature, full new battery, new napa compression tester.
That doesn't look good. I have seen oil coming out of the dipstick from having the wrong PVC valve in the valve cover but with those compression numbers I don't see that being the problem. I'll put it out there in case it can help someone else though. When I put the 351W in my 71 F100 before I dropped in the 460 I used a PCV Valve I had here in the shop. Soon after starting up that engine oil pushed the dipstick out of the tube and went all over the place. I helped a friend put a 351W in a 90's Mustang in place of a 5.0 and we used the old PCV valve. Same thing happened. On the 351W it took forever to figure out the problem. On the Mustang I knew what the problem was. All I can think of is pressure building up in the crankcase and forcing oil out of the dipstick. I wish this was your problem. Might check it just to be sure though. Make sure the PCV valve is working. Clint
thnx clint. i had just put a new pcv valve on a couple of weeks ago after this had started happening. I changed it with a new one today before doing the compression test and cleaned out the pcv hose and inlet as well. I wish it was the pcv too haha
