I drove home from school, and my car sounded fine. Then I drove to the store, and on the way there in gets this knocking sound. I opened the hood and it didn't seem to be coming from the the alternator or other accessories. I drove home(only about two blocks) and on the way it quit. Checked the oil and it was at the add mark so i gave it a quart. Then I drove to work(about 4 miles) and it didn't knock. Is it possible for the engine to knock intermitently? Any other possible explanations? Thanks ~Arnold

 

Time for an oil change. That one new quart of oil increased the viscosity of the old oil
just enough to stop the ticking/knocking.
I'd check the oil pressure with a gauge
after I changed the oil too. Your oil pressure may be marginal at idle/low engine speeds. with stop and go, city driving where the motor never really gets warmed up, your oil can easily become fuel diluted. If that's the case you'll have to change your oil more often. Its normal for the oil pressure to be low at idle when the motor is fully warmed up. But you should have between 40 to 80psi @ 2000 rpm. You need about 8 to 10 psi at idle to keep the rods and hydraulic lifters quiet. Anything less needs to be addressed. Hope this helps.

 

Thanks for the reply. That would make sense. Most of the driving I do is to work which is only about 4 miles. I usually only drive to school(30 miles) once a week because the rest of the time I ride with my sister.

The oil pressure guage on the dash doesn't really work(the guage kinda flies all over the place, jumps up and down). So if I get a "reall" guage, like a shop guage or something, where does it hook up? Thanks ~Arnold

 

There are a number of places that you can use to get oil pressure readings from. But taking the sending unit off of the fittings near the back of the intake on the driver side and installing whatever fittings needed to get a mechanical gauge on there is probably the easiest one to work with.

EDIT: BTW, how many miles are on the oil that is in the car right now?

------------------
1987 GTA L98 MD8
355, TFS Heads, LT4 Hot Cam
My GTA

The Minnesota F-body Club

[This message has been edited by Matt87GTA (edited December 11, 2001).]

 

It's got about 2500 I think so I'm almost due for a change anyway. Thanks ~Arnold