Ticking on start-up/coolant leak

1.2gees · 1.2gees's Garage

I'm having a ticking sound come from the front of the cam tower/timing belt area that's somewhat hard to distinguish. It goes away in less than 2 min. I'm guessing it to be an oil starved lifter, ideas? (I use redline 20w-50). My oil pressure is at 5 bars, and the oil light goes out as the engine is starting. This noise is only there when the engine is cold (regardless of how long the engine has been shut off), which makes me think that a lifter around the timing belt could also cause this noise. I'll try to flush the whole system if I get some time in a couple of weeks, and see if it's just a blocked passage, and it's taking time to get oil to that one lifter.

Also, I have a coolant leak but only after shut off. I'm not so sure this is a 'leak', as I can't duplicate it. Overfill the system while cold, start it up, let it warm up, not a single drop anywhere. Shut the car off and I have a nice little puddle shortly after. My oil/coolant are NOT mixing. My theory is that when I shut the engine, coolant temperature rises, increasing system pressure enough to cause a leak (or the cap spring isn't too tight, and it lets some coolant out). It seems to come from the driver's side of the RADIATOR though. BTW, the radiator is what appears to be a turbo unit, but I havne't been able to very that (anybody wanna help with that?).

I welcome ideas/opinions.
Thanks
Ahmet

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AFJuvat · 10-05-2001, 12:31 PM

Had the same thing happen to me a few weeks ago - no leaks, no nothing (I even had the system pressure tested)

My mechanic's take:
On an excaptionally hot day, if the system is overfilled, it is possible for thermal expansion of the coolant to take place causing it to spill out the overflow of the tank.

Also, based on personal experience, check the upper radiator to expansion tank hose, at one point it gets extremely close to the alternator fan - and if one of the zip ties breaks......

third possibility:

if you have inadvertantly run low on coolant in the past, it is possible you sucked in an air bubble - bleed the cooling system

Good Luck
AFJuvat

Britwrench · 10-05-2001, 01:17 PM

The ticking noise..loose timing belt

The coolant leak.. pressure test the cooling system and follow the trail to source.
Could be the water pump? If you still have the undertray on, the coolant (and make sure it is coolant) could be pooling up on the tray and running out a distance from the leak source.

All 944 and S radiators are the same.
951 and 944S2 are deeper and use a different lower support panel.

1.2gees · 1.2gees's Garage

Britwrench: What do you think I should do about the timing belt? Is this normal? I'm going to pressure test the system as soon as I can get the car over to the shop.

BTW, do you think I might have an S2, or 951 radiator? I've been told that the turbo radiator is over 2 inches deeper?

AFJuvat, I probably have some air in the system, but this is a continuing problem I've been having, so dunno...

Thanks for the replies thus far.
Ahmet

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It's all the driver...
My page over1g@hotmail.com
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Weldin · 10-06-2001, 04:56 PM

Someone please explain to me how ticking is associated with a loose timing belt -- Please enlighten....

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Scott R · Scott R's Garage

Actually I would have to agree with the above post. When the belt is cold it should be tighter. Doubt that it's the T belt. Have the oil flushed professionally with some cleaning chemicals. Then have it refilled and see if the lifter noise goes away. Could just be a blocked oil passage. You can also do this at home by filling the motor with ATF, running it for a bit then draining it, replace the oil filter and add fesh oil. Dexron will clean a whole bunch of gunk out.

Macabre · 10-06-2001, 07:12 PM

It's not the belt that expands/contracts it's the engine. Thermal expansion of the aluminum block stretches the belt when warm and it doesn't quite come back to size when cold (which is why you have to retension from time to time). If it hasn't been tensioned recently enough it will flop around a bit when the engine is cold and slap the plastic cover. You should be able to see it doing it if you run the engine while cold with the timing belt cover off. It's usually not a constant tick though but a random tapping.. not sure if that's what you're hearing or not - but it would go away in couple minutes just like you described.

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'86 951 Graphite Metallic/Tan

Britwrench · 10-08-2001, 07:30 AM

When the engine is cold and if the belt is loose it will indeed flap against the covers.
Carefully (!) put your hand on the cover and the noise can be felt. If it is the belt, remove the covers and thoroughly inspect the belts for damage, especially the balance shaft teeth, which tend to flatten off against the water pump pulley. This is also an excellent time to check the water pump.
If they are only loose; retension and check.
We find cars like this nearly every month.

Maybe the reason the belt is loose os the water pump is going out, and causing a leak?

944S2 and 951 radiators are deeper, check the lower support panel; if it is straight
you have a NA rad. Also the fan shroud is deeper to match.

Other possibilites are a cracked exhaut manifold, sticking lifter or blown exhaust manifold gasket.

If you are not sure, find a shop you can trust and work with them. You might have to leave the car ther overnight and then be at the shop when they start it from cold. Then you can be sure you and the shop are hearing the same noise.

3sonfather · 10-08-2001, 08:08 AM

1.2 you could use a stethoscope to isolate exactly where the ticking is coming from but it sounds like it is a lifter. I do wonder if 20w-50 is too heavy for these engines, especially with colder weather upon us.
I would also be suspicious of a leak in your water pump since small leaks may be periodic in nature and not readily visible when they do occur.
Keep us posted.
Scott

Lawrence Coppari · 10-08-2001, 01:04 PM

Aluminum has a high coefficient of expansion. It is about 1.3d-05 in/in-deg F. Ordinary carbon steel is about 6.6d-06 in/in-deg F. Belt should tighten when motor gets hot. Stainless steel is about 9.6d-06in/in-deg F.

1.2gees · 1.2gees's Garage

Thank you for all the replies.

I'm actually a mechanic, but haven't been able to drive for a while so I can't get my car over to the shop. I get my license back in 11 days, but I'll try to pull the covers off to check tonight, see about the belt.

The bad thing is, I'm getting ready to take a long trip with the car, and a timing belt (or any other major) failure would really ruin my trip, make me miss a lot of school, work, and waste a lot of time/money...

I will let you guys know if it's the belts or not probably sometime this week.

PS: If it's the belt, could I tighten it a bit without the tool, and leave it alone for a few weeks? (A few 1000 miles), or if it's the lifter, well I guess an engine flush should take care of that, if not I'll see what I want to do about that when I get back.

Thanks again for all the replies.
Ahmet

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It's all the driver...
My page over1g@hotmail.com
Porsche owners Gallery.../My 944

1.2gees · 1.2gees's Garage

Just pulled the upper cover off and wow those belts are loose! So loose that I didn't want to start the car... I think I'm going to bring some tools home from work wednesday, and retension these belts. Didn't see any rubbing marks, but don't need to, even if the noise wasn't this (but I think it is), this needs to be taken care of ASAP anyway.

The timing belt was less loose than the balance shaft belt, which I could EASILY knock off a pulley. Scary!

Anyway, can anybody give me an idea of how tight I should have these belts, without using the recommended tensioner? (Push down between two specific pulleys, and have it flex so much, or similar?)

PS: I turned all pulleys, there are no leaks from the pump, no noises etc. There's a good bit of oil behind the cover (specifically behind the one that sits on the engine, but the area where the belts are was clean, and dry). (I only removed the upper/outer cover)

Thanks for all the help, I feel weird knowing I could've driven on these belts, over 3k miles before I looked at them, wow.
Ahmet

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It's all the driver...
My page over1g@hotmail.com
Porsche owners Gallery.../My 944

Britwrench · 10-09-2001, 10:05 AM

That will be $5.00 please..lol

fty · 10-09-2001, 11:53 AM

hmmnn..I get a ticking also....just pull the cover off right and start car?

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Britwrench · 10-09-2001, 02:48 PM

Yes, you will see the belt flapping around.
If it gets real bad the balance shaft belt will rub on the water pump pulley and flatten the teeth off. This usually happens if the initial 2000-2500 mile re-tension wasn't done or the belt was too loose to start with.

951carter · 10-10-2001, 10:53 AM

it is not the best indicator. especially since it is reccomended NOT to twist the belts and to store them in a manner in which they will not get twisted, but, at the long runs of the belt, the timing belt should twist 45 degrees and the balance belt should twist 90 degrees. this will get you "close" to spec. sounds like you need to replace your seals also.

1.2gees · 1.2gees's Garage

I pulled the cover off, and tightened both belts a good bit. There's very slight flapping for the first 45 sec or so, when the engine is cold, if you play with the throttle, but I think it'll be OK (after that it runs about as smooth as an accessory belt). Most certainly it's better than what it was at.

The 'coolant leak' turned out the be a sliced hose, I only needed to trim it a bit, throw a new hose clamp on it, and I don't have a leak anymore.

The battery charging light went away with the new battery as well (the old battery didn't have enough juice to have the alternator produce good power, new one does), my mp3 player, and new speakers are in(I've sold my old cd changer, and head unit, than bought and sold a sony explode head unit, cd changer, 2 6by9s, and believe it or not the money I made paid for my new speakers, which are totally rewired, with the new mp3 player!). Soon I should be adding one or two subs in the rear cubbies, and a radar detector. I'm all set, get license back friday, and have about $3100 in the bank...

Thanks for all the help, I feel great!
Ahmet

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It's all the driver...
My page over1g@hotmail.com
Porsche owners Gallery.../My 944

ae1969 · 10-14-2001, 05:09 PM

Ahmet..

The timining belt if you did it by hand.... make sure you do it with the engine COLD as the engine warms up ... the belts get awfully tight..... that scared the CRAP out of me the first time I tested the belts... but its normal........

.. the trick with the 45 degrees/90 degrees is fairly accurate.... tried it and tested with the gauge.... its hard to get to the magical numbers they want for tension... but it should get you by.

besides that...good luck.....

Alex