New 924 owner with questions

JonA · 02-10-2001, 09:58 AM

In a moment of questionable sanity my teenage son and I just bought a 1982 924. It needs quite a bit of work but the body is impressively sound and there is no evidence of any collision damage. I believe it can be made into a safe and reliable vehicle for him to drive (and maybe Dad once in a while)
Anyway we are trying to learn as much as we can about this vehicle (I bought the Haynes manual) and maybe some of you would be kind enough to provide some guidance on a few of our immediate questions:
The engine (106,000 mi) runs very smoothly and seems strong and the previous owner alleges that it burned no oil. I cannot get my compression tester into place for a compression test. However, after warming up the oil pressure drops to zero and the oil warning light comes on. Is it likely that a new oil pump will solve this problem or am I looking at a engine rebuild.
Also, how much pressure typically is required to depress the clutch? It operates fine but seems hard to move based on my experiences with other vehicles, but until this car I had never driven a Porsche. It looks like a clutch job is a lot of work, nothing on this car seems to come apart easily.
Finally, the book shows a stop ring on the steering rack between the tie rod cup and the lock nut. Our car does not have the rings. Is it typical for the rings to be missing and how do you set up the tie rods without this piece to measure against.
Thanks for any help that you can provide

JonA

AMCPorsche924Powerhaus! · 02-10-2001, 12:17 PM

Hi there.
The Haynes manual has a lot of good pictures and good descriptions, but don't take everything literally in the Haynes, there are some very crude mistakes.
The descriptions of how the 924 engine works, the fuel injection, suspension, etc work are very good in the Haynes, and nothing is wrong in the theories, it is the torque specs, measurements, clearances, calculations,etc. you have to watch. You also have to watch the directness of the manual, like it says "the 924 turbo has only two rings on the pistons, no scraper". Well most seem to have three . And "the 924 turbo has 7.5:1 compression" Wel the factory manual says 8.0 .
It also says "the lambada system is easily distinguished by the shiny silver fuel distrib". Well the 924 turbo has teh shiny distrib, but there are many/all 924 non turbos that have a black fuel distributor with the lambada.

Some of the mistakes are so obvious that it doesn't matter, but, some will cause you to break things if you don't use your own head first to think things over.
Like the cam followers for example, it says many times in the haynes in bold that the clearance for the inlet valves should be 40 thou. If you have had a 924 before you know it is 4 thou, not 40, but since you are new how are you supposed to know if 40 is ok or not, other than when you start the car up and it taps like crazy. Maybe thats why these cam followers are called tappets

The manual has the specs written right in some places and wrong in others in some of the cases.
The torque specs can be wrong any where in the book, so don't use them as a "for sure".
The problem with this is that when you are doing things like head bolts, you do have to trust the haynes for being right, otherwise it could cost you 1000 dollars for a used head or something in that line. (the head specs are right, although the procedure for torquing is not always applicable or right for your certain brand of gasket you buy).

The wiring diagrams are good, and there might be one mistake in them but they are very good I have found since they are copied from the factory manual.

The cylinder head check section has a lot of mistakes, most are very obvious in that they are off a decimal or they have not been converted into different units properly.

I find that some of the Haynes procedures are ridiculous also, they work but some times they can lead you into wasting a lot of time. Like to reset the OXS it says to place the car on jackstands. No need, that is just silly.
Also some of the procedures are obscure in that it is not descriptive enough, such as: "remove the bolts holding the transmission to the car and fix the transmission".
This is not what it says I am just trying to point out that SOME, not all, of the procedures are so unexplained you might as well just not read the manual.

The manual is defintately worth 15 bucks, in fact worth more than 15, WITH THE WARNING of mistakes.
If you buy the manual following it literally, word for word, it is a loss rather than a gain. With the knowledge of it having mistakes it is very good manual, especially for the descriptions on how everything works.
It is like me selling you a chocolate bar for 1 cent that is 2 meters long, and the last centimeter has poison in it. It is a VERY good deal as long as I warn you the last part is poison, and to tear it off before you eat the now 1.99 metre long bar But it is much more of a loss if you just buy it from me and eat the whole thing and get poisoned. Sorry for the crude comparison, its all I could think of

Your oil pressure: first of all before you do anything with the car, check your oil and change it.
Don't just change the oil, change the oil AND check it. Check the oil filler cap. Find out which oil is best for your car (read posts and your owners manual etc.)
You may want to use engine flush with the oil change, but don't do it if you are unsure, research it, read posts etc.
Sometimes the oil pressure problem can be solved just with changing the oil.
You may want to drain the oil, have a look, change filter, fill with clean oil, and drain it. Then repeat again. Instead of changing the oil once, change it twice (unless the oil you are using is like 50 bucks a can, then maybe use cheap oil to drain it a few times).
If you decide to flush the engine, you might want to change the filter before you clush it and after, and change the oil more than once to fully rid the flush. The reason you might want to change the filter before you flush it is that it could get clooged fast and cause more harm than if you just wouldn't have flushed at all.

Also pull the cam cover off, and check the oiler tube that runs down the center and lubes the camtrain. Check its looseness where it pops into the head (at the front of the head where the black peice pops in). Do this by loosening the 2 or 3 cam cap bolts and trying to pull it out. If it is loose and comes out easy, replace it with a new one, because this could be causing your low oil pressure.
Also clean it, and put your mouth on it and blow into it like a flute. If it is plugged, replace it or clean it etc.

Nothing to do with oil pressure but: check your valve clearance and condition of tappets while you have the cam cover off.
Check the torque of the head bolts too while the cam cover is off.

The clutch cable can be lubricated and checked. It should not have too many bends in it and should not be maneuvered around things that it doesn't have to. Replace it if it is rusty or even if in doubt. I think there is a cheap cable you can get from another car that has to be modified slightly if if the Porsche one is too expensive.

Hope this helps

And welcome to an exceptionally handling car if you didn't already know.

Lawrence Coppari · 02-10-2001, 04:05 PM

How do you know the oil sender transducer is working properly? Sender units are relatively inexpensive so you might take a chance, buy one and install it. Seems to me that if the oil pressure were that low, you would have harmed something by now. It does not take long to cause damage.

AMCPorsche924Powerhaus! · 02-10-2001, 05:47 PM

oil sender units are 80 dollars US each.
That is with the gauge reading type. The one with just the idiot light is dirt cheap.
It could be that there is pressure, but the oil sender on the 924 is HIGH up in the head, and may be giving a false reading of what teh pressure is down low where it really matters (could be because the oil tube is loose, pooping oil out rather than squirting, easy fix)

[This message has been edited by AMCPorsche924Powerhaus! (edited 02-10-2001).]

AMCPorsche924Powerhaus! · 02-10-2001, 05:53 PM

Another thing to do is this;
-run the car
-turn the parking lights on and watch the gauge
-if the gauge does not change, forget this test
-if the gauge does change you have bad grounds and I can tell you the fix. Just cleaning the grounds will not solve the problem, but will definately help.
If you do have the symptom of the gauge changing with lights on, post a line back here.

[This message has been edited by AMCPorsche924Powerhaus! (edited 02-10-2001).]

awilson40 · 02-11-2001, 04:34 AM

I'm with them... change your oil and filter, I run Castol GTX 20w50 and I run 7 bar at speed and 3-4 bar at idle when warm.
Your car Will use about a quart of oil every 600-700 miles... They all do, so dont wory about it. Do check the valve clearances and the oil tube where it plugs into the head. Drain and flush your radiator, be sure to 'burp' it with the bleed cap. Just do all the basic maint you would on any used car with 100k miles.
I also have a 1982 924 that I have done a bit of work to, feel free to email me if you have any questions.
My car:
http://home.earthlink.net/~awilson40/

JonA · 02-11-2001, 05:20 AM

Thanks everyone for all your comments.
Concerning the oil pressure problem, I did change the oil and filter with no results. I will poke around somemore and let you know how I make out.

Jon A

JonA · 02-11-2001, 05:28 AM

Thanks everyone for all your comments.
Concerning the oil pressure problem, I did change the oil and filter with no results. I will poke around somemore and let you know how I make out.

Jon A

macreel · 02-11-2001, 03:58 PM

JonA...The purchase of a (Porsche)924 affirms
your sanity. Now, I might wonder about those
944 drivers, they're a bit singular.... I too
am a "newby" '79 924 owner, still with a grin on, enjoying every minute.

Oil pressure is important, and must be examined; but in my Owner's Manual, pg.22, it
says with HOT oil and idle you can get low
readings and the idiot light flashes. It may
be a 'normal' condition; but practice safe
automotives--check it out(level,tube,senders,wiring,filter,elec grounds, etc). Good luck; ENJOY.

lm6y · 02-12-2001, 08:21 AM

Come on now Macreel, we aren't that bad!

Those of us that have 944's just aren't that familiar with the engine in a 924, so if we don't know, we don't post. We will leave that up to those who DO know. I would hate to give info that is wrong, and could destroy someone's engine. I think all of us know that if Porsche wouldn't have bought the rights to the 924 back from VW, the 944 probably wouldn't be here today. nor would the 951, and 968 models. The 924 is the first porsche I had ever driven, and I fell in love with it. Now I'm addicted to front engined-watercooled four cylinder P-cars!

pst · 02-12-2001, 09:12 AM

I have owned 924's for 20 years and have had very good luck with them. However, there are some common problems associated with them. The oil pressure is one. I have never seen a worn out oil pump. (I have 6 core motors all have good pumps) It has been my experience that the main bearings develop excessive clearance. I have replaced these on 4 different cars and it solved the problem. Each car had .007"-.008" clearance in the mains. The crank does not seem to be affected by this so the bearings cure the problem. This can be done without removing the engine.
The oil burning that has been discussed here is usually the valve stem seals. The valve guides tend to wear and the seals harden. Replacing these can also be done without removing the head.
The clutch is also a common problem. This can be caused by a few different things. The cable, the throu-out arm bushings and the throu-out bearing guide tube. The only cure is replacement. The cable is all than be replaced without disassembling the components to get to the clutch.

AMCPorsche924Powerhaus! · 02-12-2001, 09:21 AM

Quote:

Originally posted by lm6y:
I think all of us know that if Porsche wouldn't have bought the rights to the 924 back from VW, the 944 probably wouldn't be here today. nor would the 951, and 968 models.

Shame: I think all of us know that if Porsche wouldn't have bought the rights to the 924 engine back from AMC, the 944 probably wouldn't be here.....

thamlin000 · thamlin000's Garage

Beautiful car, awilson!

drew1 · 02-12-2001, 09:14 PM

JonA,

I think you have a cable operated clutch, but being an 82 it may be a hydraulic, like 944. I'm not sure. If so, you can adjust the spring on the pedal.

That oil pressure sending unit hook up on the head can be hard to get to, but I think you can buy a VDO manual guage and line with the 10 mm fitting for around $30 to double check this. Even if your motors not knocking, low oil pressure is rough on expensive cam & lifters. Is the motor idled up high enough?

Ask some of these other boys if they have had trouble with the relief valve in the oil pump.

drew1

AMCPorsche924Powerhaus! · 02-12-2001, 11:15 PM

mainly the releif valve causes the problem of having too high oil pressure.
Like when you accelerate, the oil pressure goes up linear with the rpm, since it is not relieiving when its supposed to do so at like .4 bar or whatever it is

awilson40 · 02-13-2001, 03:13 AM

Thanks...

lm6y · 02-13-2001, 03:34 PM

AMCPorsche924Powerhaus!, My bad, I forgot. just because the car was originally supposed to be a Volkswagen, means that the engine choice could have stopped production.
Personaly, I don't care where the engine came from, it sits under the hood of a Porsche in this case, and that's good enough for me.

JonA · 02-14-2001, 05:53 AM

Concerning my problem with low oil pressure: I pulled the valve cover yesterday and removed the oil supply tube. The o ring was completely gone where the tube 90's into the bearing cap and the little plastic 90deg. fitting fell apart in my hand. I will fix this and run the engine before going any deeper. I can see how a lot of oil could bypass at this point and if that will significantly lower the pressure, maybe I am in good shape......
Two more questions: What years was the 924 made and are parts generally interchangeable throughout those years? What is a good source for used parts?

Anyone got any experience with changing tie rods. What I have doesn't correspond with the description in Haynes.

Thanks everyone, this site is great.

AMCPorsche924Powerhaus! · 02-14-2001, 09:16 AM

Quote:

Originally posted by JonA:
Concerning my problem with low oil pressure: I pulled the valve cover yesterday and removed the oil supply tube. The o ring was completely gone where the tube 90's into the bearing cap and the little plastic 90deg. fitting fell apart in my hand. I will fix this and run the engine before going any deeper. I can see how a lot of oil could bypass at this point and if that will significantly lower the pressure, maybe I am in good shape......
Two more questions: What years was the 924 made and are parts generally interchangeable throughout those years? What is a good source for used parts?

Anyone got any experience with changing tie rods. What I have doesn't correspond with the description in Haynes.

Thanks everyone, this site is great.

Hi JonA.

That oil tube of yours, it could be a problem in that the PO has driven the car/run it like this!
Look at the tappets, make sure they are not dished and check everythign for wear.
When I bought my car, the tappets were in great condition, even though my oiler was loose and leaked like a siv....
I think you might be able to by that plastic fitting?
Or the whole oiler?? I don't know, I am looking into it (I had a spare oiler so I didn't need to buy one, but I am gonna get one since even my spare oiler is still loose)

AMCPorsche924Powerhaus! · 02-14-2001, 09:40 AM

Quote:

Originally posted by lm6y:
AMCPorsche924Powerhaus!, My bad, I forgot. just because the car was originally supposed to be a Volkswagen, means that the engine choice could have stopped production.
Personaly, I don't care where the engine came from, it sits under the hood of a Porsche in this case, and that's good enough for me.

your right.
I like driving my 931, I don't care if its from Mars, its fun, and it drives like a go cart with a v-12 at the back.
I just like research.
If I cared where the engine came from, I would have sold my car by now.