Aey

Happy Independence Day and hello from Thailand.

I just got 1982 RHD 944NA with about 60,xxx KM about one month ago. I don’t know when was the last timing belt change, but I plan to change it immediately when I get my water pump kit from the State.

I recently have white smoke coming from water pump/oil cooler area and I need your help to identify the source of the problem. Here is the story. I try to explain in detail, so it might be long.

Overheated: The engine seems to run perfectly, until I got overheated last week. It was in redline for a minute and I pulled out just in time (I hope). Coolant was shooting out from the reservoir overflow connector. My car did not have the overflow hose, so the coolant was shouting out all over my engine bay. I waited for almost an hour for the engine to cool down, refilled reservoir with drinking water and drove about 10KM back home. I have to stop 1 time on the way back because the temperature started to pass ¾ mark. I shut down the engine again and saw coolant shooting out but not as bad as the first time. The coolant color was brown and feels a little muddy like it hadn’t been change for years. I think there was no oil mixing in there though. Finally my car is sitting safely in my garage.

Clogged Radiator: I drained my radiator next morning (opened both radiator drain plug and engine block drain screw), and found out that there're many solid deposits in my water cool system. I think this might have clogged my radiator and caused the over heated problem. Also, I found out that my car was running without thermostat. I then used “15 minutes radiator cleaner” to clean all the deposit in my system. I flushed my system with plain water many many times until the drained water was crystal clear. I followed 944 coolant bleeding procedure, and I’m sure that there was no air pocket in my system. I drove my car as normal, and the temp gauge never reach ½ mark.

White Smoke: Everything seem to be OK, until I noticeed some little white smoke coming from in front of the engine. I shut down my car immediately, when I saw the smoke. At first it wasn't clear where the smoke was coming from, but the smell was like some kind of rubber burned. So I suspect that my water pump roller might have seized. I opened my timing belt cover to check, but timing belt and rollers seem to be in good condition (and I have the updated water pump already). However, I found out that my timing belt rubbed against the back cover (although this is not the source of the white smoke, I really want to know why it rubbed?? and how to solve this problem?).


I started my engine again with timing belt cover removed and this time it’s clear that the smoke was not coming from the timing belt, but it was coming from water pump/oil cooler area. Here is the video, https://vimeo.com/99990679

Little Oil Leak: I checked closely in my water pump/oil cooler area and also under the car, and found out that there’s little oil leak.


The whole area was coated with oil, but not much and there was no oil drop on the floor. The strange thing is that the smell was like “rubber burned” but to my knowledge; there is no belt or moving rubber in that area.

Can anyone tell me what is the source of my problem?

I hope the problem is not serious. I’m now waiting for new water pump, gasket, thermostat, timing belt, balance belt, oil cooler gasket kit, front engine seal kit, and all 4 rollers to arrive. I want to have all parts ready when I’m in there.

Or am I having a bigger problem like; blown head gasket? or cylinder head distortion from the overheated last week?

Please help identify the source of my problem and how to solve it. Thank you.

mel_t_vin

Did you really run the car past redline for one minute?

These cars were designed with a built-in, DME-based, rev limiter [6900rpm?]. Have you ever tripped it?

Re: your smoke...when someone changes the oil/filter and doesn't pay attention to detail [and spills/splashes oil], that's what the result looks like. And since you pointed out that the lower front corner of your cam housing is moist/wet with oil, guess where the wind blows those droplets? Look straight down...correct, onto your headers, most likely runners #1 and #2.

Easy and free...put a torque wrench on your cam housing bolts [OE spec is 15 ft-lb/20 Nm, if I'm not mistaken], working from the middle to the outsides in a criss-cross pattern:

8 4 2 6 10
9 5 1 3 7

That might stop your small leak and/or your smoking.

Re: your rubbing cam belt...I'll let someone else, like Van, shine some light on that subject. I believe he put up a 3-part "engine building" YouTube video that discusses the correct orientation of the belt rollers/idlers. If I remember correctly, if one of the aforementioned rollers/idlers is not properly mounted, the belt can/will rub.

Doesn't sound like your issues are too serious.

VirginiaF1

Mel, the "redline" has too be coolant temp and not rpm's..
Correct Aey?

mel_t_vin

Good point...re-reading the original post, "It was in redline for a minute and I pulled out just in time (I hope)", that would make more sense.

Aey, due to voltage drops across connections and resistance in the wiring, factory gauges can be inaccurate. Although, since you mentioned your engine burped up coolant on two occasions, your engine probably overheated [to some degree] due to that clogged radiator. Cleaning and flushing your engine/radiator was the right thing to do.

Aey

Thank you for your replies.

VirginiaF1: Yes, that's correct. I mean the temp gauge was at maximum for about 1 minute. My gauges were not working properly and I did not trust my temp gauge, until I saw stream for water coming out in front of my car. As soon as I saw that I shut my engine down immediately.

Mel: I cleaned and flushed my radiator already, and now it looks like overheated problem is solved. As for the white smoke problem, I'll check cam housing bolt and seal as you advised and will post back the result soon.

Aey

So the oil leaked from cam housing to the header. Re-tighten the bolt and it's fixed now. Thank you everyone.

mel_t_vin

Easy and free...not often you get to put those two words in the same sentence as "Porsche" and "repair". Well done.

What ever came of your cam belt issue?

Aey

I think I have a bigger problem now. Couple days ago, I tightened all outside cam housing bolts (9 bolts close to the header) to 15 ft.lbs. The leak was better but not totally disappeared.

So today I decided to remove 6 seal plugs and tighten 6 inside cam housing bolts, and I found the problem!! Somehow 2 of the cam housing threads were stripped and 2 bolts are just sitting inside.



With long 6mm hex socket, I can easily turn the inside bolt freely by hand (without a wrench).

What should I do? How can I re-thread the aluminium housing?

Tiger03447

Sounds like it might be time to remove the cam housing, and helicoil the threads that hold the cam housing on to the cylinder head. Sounds like the PO or some dumb mechanic wasn't too kind to the car. Most, if not all of these holes, are blind holes. If you are not too mechanical, this should be entrusted to a good shop that has/is /are dealing with Porsche cars. The holes must be square to the cylinder head. Unless you use some sort of levelling fixture on the drill to keep it in the correct place, disaster with an off-center hole can ensue. Hope this helps some. Just my .02 cents worth.