Loud clunk on start up
 

So occasionaly, not all the time, whenever I turn over the car I can hear the starter cranking then there is a loud clunk and I have to turn the car over again. But the second time it always fires right up and I have no other (known) mechanical issues. Any idea what it could be?

87 944T

Could you get a sound clip of it?

I don't know if I understand your problem correctly, but sometimes my car would seem like it fired too early while cranking and send the motor spinning backwards, which made an interesting sound as the starter was still engaged.
I think it was because I never had the heat shield between the starter and the exhaust, because a new starter solved the problem

Something loose in the bell housing?

Maybe your starter itself is loose,,, causing it to twist and 'CLunk'

I wonder if the motor mounts might be shot or a loose exhaust system. Usually that's when the motor is subject to torque transients.

I know this is going to sound stupid, and I don't have a reason why, but mine has always done the same thing.
Here's how I avoid the problem. It seem to rarely happen as long as I start the car by
- Putting the car in neutral
- Not putting the clutch in.

Again, I know this is completely crazy, but It works for my 951

does the car start without the clutch in? i start in neutral most of the time anyway though.

its not the exhaust but it might be the starter is a little loose or something.. i will try to get a clip of it. but it doesn't do it everytime so i might not be able to replicate the issue! thanks guys.

yep, fine by me
 

Yes, at least mine does. I still have to double check and think about it every time I go to start though. No clutch in neutral car starts fine..

Leaky injector.

Pull the injectors---good time to get new seals--and put each in a plastic baggie with a piece of brown paper bag. If they leak overnight, the brown paper will show a stain.

It could also be a faulty FPR or FPD with a cracked leaking rubber diaphram. Fuel gets in the vac system and into the air intake. Pull the vac lines and sniff for gas or moisture.

Pure speculation.

John

Thanks John, I will try that since the car is going to be down this weekend anyway. Is that a common issue when an injector seal has a leak though?

No, it was just a quess. I was thinking along the lines of a small "backfire" issue causing the "clunk".

I like the idea of checking the bolts to the starter. If you pull the starter, you should check to see if any of the PP starter ring gear are chipped or missing. This would be the best reason of a "clunk" while grinding the starter.

GL
John

Mine does the same thing. My starter didn't look chipped or broken when I put it back in, but the next time I can find a spot to work on my car, I'll pull it and take a look-see. I was also thinking it might be an injector, so it's good to hear that others concur.

I tried not using the clutch/putting the trans in neutral. . .that did not help my clunk. I"m thinking that every time I start my car I should be taping, because so far there have been no set of circumstances that are a common factor. Other than car and driver. . .;)

Mine had a clunk where it would seem like the starter and engine would stall together. After tons of researching on here I found a few buried threads where there was talk about a magnetic shield on the reference sensor being lost. Something about magnetic pulses in the later model starter (slimmer version) interfering with the reference sensor. Here's a video that I took when I was trying to figure it out on mine...
The clunk is more audible in person as the chime and exhaust seem abnormally loud in the video.

Anyway, while all this was happening I managed to mangle the crap out of my starter solenoid (stripped out the tread on one of the studs) so ended up buying a new aftermarket starter. Works wonderful now.