Been lurking awhile and have been able to find answers on previous problems but this now has be stumped

This ****in' car...

To start (maybe this is all linked together), couple months ago the car wouldn't start. No clicks or anything. I heard about the passkey stuff so I got my spare key and it worked fine. Figured that other key was worn out or something. Been on that for awhile and a month ago I was driving and the security light started blinking. Got to my destination and turned the car off. Started back up fine without the light. No clue why that happened. Two weeks ago it wouldn't start again, called a locksmith and they insisted its the ignition and not the key and wanted like $220. Right... Waited a few minutes and it started. Came home, soaked the key in alcohol and cleaned the hell out of it. Been fine ever since.

Been having a few leaks and running problems so I decided to do a little tune up a couple weeks ago. Replaced spark plugs, spark plug wires, upper intake manifold gasket, lower manifold gaskets, valve cover gaskets, intake filter, full PCV system (all hoses and valve) and MAP sensor. Been good since then, think that stopped the coolant leak but still an oil leak somewhere.

The problem that hasn't gone away... Intermittent! Sometimes it starts up fine, but lately that is becoming less frequent. Other times it will start and the RPMs drop really low when it occasionally can't catch itself and dies. Sometimes it will catch itself and rev up to like 3k and stay there for a few seconds with a slow descent of RPMs to a normal idle.

The other problem that is getting worse may be a little harder to explain. When starting, after a revolution or two it almost backfires but I hear a burst of air that seems to come from the engine bay, not the exhaust. Before I replaced all the PCV stuff it would actually blow that out of the intake manifold with some smoke and of course a terrible idle unless I could slip the PCV valve back on the hose.

Yes the CEL is on (when isn't it with this piece of **** haha) and I haven't gotten it checked in awhile.

 

Ouch. That's a lot of work, hopefully you can get it right. Check your IAC valve, that may be why it's cutting off. Of course check fuel pressure also. Check all of your vacuum lines... You may have a leak. As for the oil, it's probably leaking from the rear main seal.




Check the obvious oil pan and oil filter gaskets also.

Good luck...

 

Yea, I have a feeling the rear main is where the oil is coming from. Not really worth fixing to me.

I am wondering if this thing some how jumped the timing, but then again it runs fine after these start up problems most of the time.

 

sounds like an emissions issue, check to see if the catylitic converters plugged or broke. After you check that you can unplug the 02 sensors and that should atleast lessen the problem of the idle.

 

The oil leak is probably the oil pump drive seal leaking and running down the back of the motor. The oil pump drive is located in the valley on top of the motor at the back where a distributor would be in an older motor. The seals leak on ALL LQ1 motors. Most likely where your leak is coming from.

It could be possible the timing jumped a tooth on the belt. If it has been a while since the belt was changed (if ever) then the belt could be worn and stretched. How many miles are on the current timing belt? If its over 80k then it needs replaced.
Check out this write up. Its for the older 91-95 motors but can be usefull for changing the belt on the 96-97 motors.
60DegreeV6.com - Cam Timing Picture Walkthrough

 

Ya' know something, I think the last time I had the CEL checked it had something to do with emissions. I will have to get it checked again and see.

Man, a buddy of mine who works on GM cars all the time asked about that damn seal. Had no idea where it was or what it was for that matter so that didn't get messed with. Does the intake mani have to come back off for that? Don't think I care to do that again haha.

I've done a timing belt or two on a previous car and hated every minute of it. The car has 160K on it, and I have no clue when/if it was ever changed. Judging by what I saw with the plugs and other things I replaced a few weeks ago, probably never!

 

The right (rear) head needs to come off to get the OPD out to change the seal. The head hangs over the drive and keeps it from coming out. Some people have loosened the hold down and pulled up on the OPD far enough to squeeze some RTV around it and then tightened it back down.

As for the timing belt I highly recommend changing it or having someone do it for you. The 96-97 motors are interference motors so if the belt breaks while the engine is running you risk bending the valves and damaging the pistons.

 

Yeaaaaaa car definitely isn't worth pulling a head off.

I'm aware what an interference motor is and consequences... From experience lol. I need to grab my timing light and see what's up.

Btw, thanks to everyone do far for the replies!

 

Well after some research and asking some mechanic friends, I think it may be a crank case pressure problem. Removed oil cap and it started fine. Got a new PCV and hoses for the system so now I'm stuck wondering. Going to keep trying the oil cap thing to see how consistent it is. The PCV is new but it's not an OEM one and I now remember from past cars that off brand ones can still be bad even when new.

 

Saw this and wanted to add my two cents.

mrl390 is completely right.
The oil pump drive leaks oil after about 60-70k miles and the seal needs to be replaced. You definitely need to take the heads off. When I bought my monte from the dealership, I had to completely rebuild the engine from the bottom up. Doing the timing on this engine is a nightmare also. As for the stalling problem and the high / low RPMs, try replacing the fuel pressure regulator. I had a similar problem that resulted in a clogged fuel filter regulator. crazy what a little piece can do.

If your engine is beginning to overheat by notice of the dashboard, you may need to take the heads to a shop and have them planed out or milled down to make them flush with the block, which is what I had to do. Since they're aluminum, they can warp after so long. Also, if you do happen to take the cams off to do the timing again, you will need to get yourself the cam hold down tools. You can probably find them on ebay for less.

Good luck bud.