Topic: Would too much oil cause my truck to idle rough?

[PeterPaul383]

So my truck has been running pretty bad ever since I changed the oil. It ran fine before the oil change. The idle is fine in the morning but would progressively get worse the longer I drove (stall when I came to a stop.) The motor is a 22R with a Weber 32/36 Carb. Another thing I noticed is that I've been getting a little bit of oil into my carb through the hose that runs from the air cleaner, to the hole next to the oil fill point. What I was thinking is that I overfilled the oil and that oil has been causing it to idle bad. My reasoning behind this is that in the morning it runs fine because all the oil is settled but after the engine has been running for a while, the oil gets mixed around and clogs up the the air being fed into the carb somehow. The engine runs fine at high idle but when I am at idle, it dies. My question is, does this sound like a valid assumption or is it something else? Thanks!

[redneckcustoms13]

First thing I would do is check the oil level. If it is too high drain some. If it's not too high it sounds like you have some blow by from weak oil rings possibly.

[OVRAROK]

do a compression test, pretty easy to do, can rent tool at parts store, will tell you a lot

[PeterPaul383 [OP]]

Thanks for the info guys! I changed the oil but that wasn't it because I was actually a little low on oil. I bought a compression tester so I will check that tomorrow and report back with numbers.

[PeterPaul383 [OP]]

Okay, so I checked the compression for all 4 cylinders and they all read about 135 psi. My Chilton's says I am supposed to have 156 psi. The plugs were a little brown as well. Could low compression be the cause of my problem?

[redneckcustoms13]

Looks like it to me. Either you have valves not seating to seal well or you have rings worn. If it's consistent on all cylinders I'd lean toward rings. I doubt all the valve would simultaneously develop the same issue.

[Gillesdetrail]

Well, how high is the oil above the maximum point on the dipstick? Too high can cause foaming and lower oil pressure, but shouldn't cause the motor to stall at idle. How did you do your compression test? With engine warm, full throttle? Also make sure you are getting no fuel in the engine while cranking (plug carb line and let the engine run out of fuel is one method, or bypass to a fuel can), then add oil in each cylinder and test again, this will show condition of rings, some testers read lower or higher than others, the fact that the numbers are all the same is a good sign, so 135 psi may not be that bad. Did you use a quality oil filter? What grade of oil did you use? In my opinion, anything above 3/16'' (or 5mm for canadians like me)vabove the maximum point on the dipstick is not good. Also, I don't see how it could do that after an oil change, unless you really put a lot more, which I would drain right away to the correct level. It may be another problem, did you knock a vacuum hose loose, vacuum leak at carb baseplate?

[PeterPaul383 [OP]]

Well, maybe I'll just do that 3RZ swap I've been wanting to do haha. And the oil is where it should be now since I just did an oil change last night. All I did for the compression test is screw the gauge in and hold the key for about 5 seconds. I used a Toyota oil filter. There is a small vacuum leak but I don't think it is big enough for the engine to die with the idle set so high.

[redneckcustoms13]

Man it seems more to me lie yiu have some trash in your carburetor .

[PeterPaul383 [OP]]

I tried rebuilding the carburetor about 3 months ago and that helped a little but it still didn't run very well and it progressively got worse.

[redneckcustoms13]

Just because you rebuilt it doesn't mean you got all the passages clear. 1 small piece of trash can make a big issue

[PeterPaul383 [OP]]

Well I'm pretty sick of not having any power anyway. I think I'm just going to do an engine swap. The local shop says they can do a 5vz-fe Swap for me so I think I'm just going to do that. Thank you for your help!

[PeterPaul383 [OP]]

Hey, just thought I'd keep you updated. It was the carburetor. I got a new Weber 32/36 and put it in the other day and it runs perfectly. Thanks again for all your help!

P.S.

What are your opinions on a propane converted 22r? Just pondering the possibility of it for the future.