Last night, my car became very lumpy…idle would be at 750rpm, but it was very lumpy, as in it was ‘pumping’ out the exhaust. runs kinda lumpy at low rpm, but otherwise it was all good. Still made as much power.
I thought ok, I better do my valve adjustment, since I’m a little overdue with it, and last time my valves were out of spec my car was lumpy at idle, but I didn’t recall it being lumpy at low rpm.
So I’ll give that a try.
SO I figure I’ll do a compression test this morning since the plugs were out (car was warmed up cause I had to drive home from my girl’s house…)
:uhoh: :uhoh:
1: 240psi
2: 235psi
3: 230psi 4: 120psi???
I don’t seem to be burning oil though?? (well, I am, but it’s valve seals, my #3 spark plug was wet when I pulled it out; #4 was perfectly dry…)
Help me out guys…
I will buy some oil later today and do a wet test on #4…
what rings do you have? did you drive it very hard before this started happening (any trips to 120, for example?). Sounds like your engine detonated(did it happen after a fill up?), but thats just speculation, ill do some research and try to help.
Max, two recommendations. First, repeat the dry test and make sure the gauge is screwed all the way in. I ran into low numbers once when the gauge was a little loose. Second, make sure you car is WARM when you run the compression test. Although it shouldn’t make that much of a difference. And lastly, do the wet test. Let me know if you need any help.
Max, a long time ago when a buddy of mine installed a cam on his VW and had set the timing incorrectly and bent 2 valves in one cylinder, the car ran, but ran extremely lumpy, sounding almost like a lawnmower. Did you run the car hard or did anything unusual happen before this occurance?
OK, so i called up my friend and asked him if he ever had the kind of prob you have. he has a turbo B16 powered civic h/b, he said he did a valve adjustment, and one of his valves was slightly bent. he was sputtering when he accelerated and had crappy sompression in one cylinder, but his idle wasnt very lumpy to him ( he has some aggressive cams, tho)
Hey Max, what valves are you running?? I have a crapload of LS parts sitting around so if you need a part like that just ask and I will send whatever you need up your way.
i’m in the process of pulling my head off but not yet done. my car was kinda lumpy and i think i bent 3 valves in the #4 cylinder. is it bad when you can move the valvespring retainer up and down at an angle with your finger. b/c mine do that.