Hi folks,

I have a problem with my 1980 Cutlass. It's got the 307 V8 with 3 speed auto trans.
I had some starting issues when its cold and/or moist outside. Then after startup it's shaking and feels like it isn't running on all cylinders. Sometimes it even stalls a few times. But after a half mile or so of driving everything is fine.
I replaced the ignition cables, distributor cap and runner. Spark plugs are still original because the ones in the set i bought where wrong (engine didn't run well and even misfired).
This didn't solve the starting issues and now I have a new problem. When accelerating the engine makes a ticking noise. It almost sounds like valve issues, but it's only with a certain amount of throttle. When letting off the throttle the noise disappears. It's also not noticable when the trans is in park. So I can't localise it in the engine bay.

Also I recognised a bit of Oil under the car. But the oil level in the engine is still ok. Maybe its just because the car had some "rough" drives at high speeds lately and the engine is just "swetting".


Any ideas what it could be? What I should check?
I hope it's no big problem.


Sorry if i make some mistakes with the english language. I'm from germany

 

What your hearing is detonation (pinging). You need to check your tune. part of your other description leads me to believe your choke is not operating properly.

 

Thanks for the fast reply.
By tune you mean the ignition timing?
Is it possible to mistune it just by changing the distributor cap an the runner? I didn't change the distributor itself.

Ok, i thought about the choke system myself, but haven't checked it yet.
Thanks for the advice!

 

I'm just going by your description of the noise and the general causes. The simple things is what I always check first.

 

Ok, thanks. I will check and report

 

You might have an exhaust leak.

That sound could be heard when accelerating and subside or silent when cruising or letting off.

You need to check or confirm your ignition timing.

 

I would check choke tension and the choke pull off setting, they are adjustable. I had a leaking pull off on a 307, idled like crap and shook. Those plugs are probably worn and have a huge .080" gap, really hard to jump the gap when they are worn out. I think .050-.060" gap is plenty enough when you replace them.

 

Today I checked the choke and it seems to work (the vacuum parts). I only readjusted it.
I also checked the ignition timing. According to my manual I don't need to pull a plug or put a bridge in aldl (I can't find the plug, tough).
The marking plate for the timing ranges from -4 to 16 but the marking on the rotating part is a bit away from it. I guess something like 24 to 26. Now I'm not sure if this is correct. Or do I need to disable HEI? Is there another way, if I can't find the aldl plug?
And what is the correct ignition timing? The internet says 20° but my manual says 15°. I don't have the label on the radiator fan housing.
Thanks alot!

 

your car may not have an aldl, i believe most 1980s were not computerized.do you have a vacuum advance on the distributor? does your carb have plugs at the front of it for mixture control solenoid and throttle position sensor?if it has an aldl it would be below the steering column at the bottom of the dash.

 

Yes, there is a vacuum advance on the distributor. For the carb I'm not sure, but I can't remember any plugs at the front of it.

I searched the area around the steering column, but there was no ALDL plug.
I think you are right, and my car doesn't have one.
Do I have to disable HEI in another way?

I readjusted the timing to about 15 to 16° today. Car is running but the ticking noise is still there.
Startup seems to be better with the adjusted choke. But it's not cold enough to really check it.

 

Is the ticking noise present at idle? Perhaps you have some worn rockers or an exhaust leak. Is this a different noise than what you described in your first post?

 

you need to remove vacuum hose from distributor,plug hose and set idle speed to check timimg.with a vac advance you don't have computer

 

I unplugged the vacuum hose of the distributor and checked the ignition timing again. It was at-2°! I adjusted it to about 15° according to my repair manual and assembled everything. A short testride was fine. Engine is running better than before.
But the ticking noise is still there.
@oldcutlass: It's the same noise as I described at the beginning.

I start to think that the noise may come from the water pump. Some time ago I had heat issues because radiator cap was defect. At one time the cooling system was running dry because I didn't notice that the water was gone. Maybe the pump took some damage from that.
Water pumps are fairly cheap so I ordered one to eliminate the possibility. I hope it arrives before the next weekend so I can install it.

 

Detonation does not happen at idle. Your going to have to follow the noise until you track the source. The water pump would make noise if there were bearing issues, usually the fan will wobble and the water pump will leak out the weep hole.

 

Ok, than maybe I found the issue. The fan wobbles and the area around the pump is wet.

 

be sure to verify before installing that the new pump is the same length as the old one, and the radiator hose nipple is the same size.

There are three different water pump lengths
two different inlet nipple diameters
and a few other less consequential differences.

Your WP is almost certainly the uber common #4 casting with the 6.1" [155mm] overall length and 1-3/4" [45mm] inlet nipple.

 

Little update. I replaced the water pump and fortunately it was a perfect fit. But the noise is still there.
When the belts were already off i checked the other devices and recognised bearing noises from the air pump and the alternator. So I ordered them new and replaced them.
I also replaced the worn spark plugs with correct new ones.
I also checked the headers. Two screws were a little loose. I retightened them. I also layed down under the car while the engine was running, and the exhaust seems thight. But it all didn't help. The noise is still there. It's driving me crazy. The car is running fine but that noise while accelerating is annoying.
Maybe the catalytic converter? How do I check this? Tapping it with a screwdriver and listening if ther is something loose inside?
Is there anything else?
I hope it's no rockers or bearings. But I think they would be also noisy in idle and low throttle driving.
Any advise is highly appreciated.
Thanks alot.

 

[QUOTE=Jecol;804495]Hi folks,

It almost sounds like valve issues, but it's only with a certain amount of throttle. When letting off the throttle the noise disappears. It's also not noticable when the trans is in park. So I can't localise it in the engine bay.

If you can't hear the tick from the engine bay or under the car when running, It could be you speedometer cable Ticking and needing replaced.
Just a thought , I hope this helps.
Cheers
Eric H

 

Would that disappear, when letting off the throttle? I thought the speedometer cable is only depending on the speed of the car.
But i'll check it anyways. Thanks.

 

when you say you replaced the air pump do you mean a/c or a.i.r pump/smog ? if it has an air pump try running it with the belt off the air pump. those pumps can make an awful fluttering noise or maybe one of the tubes connected to it are leaking.

 

I mean the a.i.r /smog pump.
Tomorrow I have a day off and will check it without the belt.
Is there a good way to find a leak if thats the problem? (I doubt that the pump is it, because it's brand new).

 

New update:

I took off the belt from a.i.r pump and alternator (one belt) and and drove a short round. Noise is still there. So I put the belt back on and thought I'd check the ignition timing again. It was still at 15° as I adjusted it last time.
Haynes Repair Manual says the 1980 needs 4° advance. For me this seems a little too less, but I tried. It didn't help and even made it a bit worse (not sure about this).
A little research in the web told me that my engine is no 307 but a 305, because the starter motor is in the passenger side and the oil filler cap is an the rocker cover. ( I can't find the engine code).
Haynes says 15° for the 307 and 4° for the 305. So what is right now? My feeling says with 15° it's running better and sound healthier.


And I'm a little bit in an dead end with searching for that freaking noise.
How can i check something that only occurs while driving...


One idea i got is maybe it's something with the EFE actuator. Its not connected to the valve becausethe welding points broke off. But i can't move the valve anyways, so i don't really think that this could make the noise by flattering or something.
Is this required for emissions?
The needs technical check with emissions this month and I don't want it to fail.

 

I found it!
Finally i foundit. While searching for an exhaust leak i figured out that the exhaust had contact to the cars body on the hanger point where the downpipe meets the pipe going to the muffler. One of the preowners cutted a piece of tire (the continental logo is still readable ) and it got porous. I installed a proper exhaust hanger and the noise is gone. Sometimes is really the easy things.

I tried to pass inspection but failed because of the oil leaking engine/transmissing, a worn steering rod end and malfunctioning parking brake.


Thank you all for your tips and advices. I have the feeling that this wasn't my last problem

 

Glad you found it, the odd noises as you found out can be tough.