New S2 project underway

robdimond · Jul 16, 2011

I've been the proud owner of an '89 S2 (somewhat infamous as the 'Red Shed') for a couple of months now and thought I should introduce myself and my car, as well as seek some advice on some current issues.

The car has 182k miles, and was a bit of a money pit/labour of love for the PO (well documented in online forums and in porsche post!). I wasn't afraid of taking on a project since I'm an engineer by trade and have done reasonably major work to previous (less interesting) cars before.

In my tenure already I've spent quite a bit on a sill restoration job and replaced the top and bottom tensioner pads, tensioner j-tube, crush washers and cam cover gaskets. The sills had some serious rot that had been filled before, but luckily was very localised so my local bodyshop could do a solid repair with new metal. I also reverted the cone air filter induction kit that had been fitted back to the stock setup.

See post here for my tensioner horror pictures:

http://www.944online.com/cgi-bin/forum/forum.cgi?board=9442S;action=display;num=1305390189

I inspected the tensioner after driving it home and found the top pad to be completely broken, hence an emergency repair. I did not replace the chain because it and the sprockets looked in good shape, it's possible that the tensioner is near the top of it's travel, but it still keeps the chain under tension.

There are some minor foibles that should be straightforward to fix:
The sunroof gears are stripped, just waiting for a free afternoon to put the new gears in and check/adust the torque of the drive motor.
The heater matrix has been bypassed with a new hose. I suspect to fix some combination of a heater matrix leak and the heater being stuck on full for the last few years.

However, some more major stuff has cropped up with about 1500 miles of driving (mostly in one round trip to Cornwall from London).

There is some oil consumption (just under a litre in 1500 miles).
There is a ticking noise from the cam cover area after a cold start which goes away when the engine warms up (5-10 minutes). I suspect this is a dodgy lifter? It is not loud enough to be audible from inside the car.
Recently the engine is sometimes rough when idling and under 2000 rpm, only when warm, sufficient for the car to be jumpy when moving around car parks, for example.

I need some advice on the next step. Firstly, an MOT and an oil change are due, then a compression test to see how mechanically sound he is.
Next, my thinking is that the cams should be taken out to inspect the lifters (see if they push down under finger pressure) and valve springs, replacing the chain while they are out. Does this sound sensible? I assume once the cams are out the lifters can be removed using a magnet and the springs are visible just underneath.

Clarks garage talks about removing the cams without the special tool by carefully slacking off the bearing caps. Has anyone tried this procedure?

Another option is to bite the bullet and go to a specialist (No 5 garage is literally walking distance from my house) at least to get an opinion. If it's several hundred quid to get a professional to replace a couple of lifters and the chain, makes sense to go that route. Also, I'm not an expert on these cars and could spend a fortune swapping out fuel regulators, distributor caps and leads to no avail. On the other hand, if it's a few thousand to remove the head and rebuild it, I'd rather have a go myself. It's not the end of the world to be off the road for a few months.

Alexw · Jul 16, 2011

Hello and welcome!
When I bought my S2 it had similar oil consuption which turned out to be the oil piston rings, it was holding compression just fine though. I had no confidence or facilities to start work like that so I had the work done for me by EMC.
The heater problem is a common one, its just a plastic clip that breaks IIRC, buts its in a very hard to reach area.
Regarding the ticking, maybe the oil is too thin? I took my car to a local "Porche" specialist and they put 0w40 in, but only told me after I rung them as it wasn't listed on the invoice. The injectors can be very "ticky" as well, but as you say it goes away it wouldn't be them.

robdimond · Jul 16, 2011

Hi, thanks for the reply. I'm not sure which oil is in there (other than it's castrol magnatec shown on the invoice). I've been topping up with 20w50 though. The oil pressure is good at least... 4-5 when cold or revving and 3ish when hot and idling. It is due an oil change and I was thinking of putting Valvoline VR-1 20w50 in since the motor has never been rebuilt.
I actually thought that thinner oil would be better for the lifters but perhaps worse for the bearings?

It's certainly not the injectors... when it warms up the other ticking goes away and the injectors can be heard clearly.

I heard about the clip thing, but I think the matrix has also been leaking and someone seems to have bodged in a plumbing type valve on the heater circuit (doesn't look original!)... a dashboard off job it seems on RHD cars.

I've heard of EMC and that they are very highly regarded. Do you mind me asking how much your rebuild set you back? I think it's on the cards as I intend to keep the car a while.

Alexw · Jul 17, 2011

I believe the thinner oil gets into the lifter quicker and can also drain quicker, but I'm guessing this is happening pretty much over night?
Check the exhaust manifold nuts as well, I recall reading when they get loose they can sound tappety until the area warms up and they quieten down again. Failing that the several guys in the US like "Seafoam" which is an engine "cleaner" I guess you could call it, supposed to work very well if the lifter has got gunk in it.

Thats exactly the oil I put in when I topped mine up (frequently), it didn't do much to stop the consumption in my case though. You could easily smell "burning" oil when you opened the window. But mine was leaking through the oil rings and the valve seals at the same time

Have you noticed any smoke when driving? Check when accelerating and lifting off, that might help to diagnose either vavle seals or piston rings

Gotta love bodge jobs! Again though I don't recall hearing of the heater matrix leaking much in past on these cars. Maybe the clip failed so it was always blowing hot air so the bodge was put in to keep it cool in summer and switch the valve on in winter? The thought of that is making me laugh I must say.

I don't think the rebuild is really comparable as mine was an engine out, head off, top and bottom rebuild. I don't have the receipt to hand but they did a lot of work - the valves were sent away to have something done to them that I can't remember - bronze seals I think. Also all new bottom end bearings and I think they slightly honed the cylinders and fitted oversize rings. Also changed the tensioner, chain and all the belts and skimmed head. Plus a new clutch as the P/O fitted the wrong one and it was almost down to the rivets. Can't remember anything else offhand but it was £2.5k inc VAT. I'd done plenty of overtime in the months leading up to pay for all that

Considering the amount of work I think thats an excellent price - they are engine and gearbox builders who happen to race Porsches, so you don't get the silly premium some places put on for the Porsche badge (£100 an hour plus!)

As you can imagine the difference was night and day! I could tell the difference as soon as I pulled the car away for the first time.

EDIT: For terrible spelling

robdimond · Jul 17, 2011

I also posted on 944online and someone there recommended Seafoam. I've read elsewhere though that stuff like this can dislodge all the gunk (good) but then it gets stuck in all the oil galleys (bad). Maybe just the oil change for now...

There is no smoke evident, although the PO said it used to smoke at 4000 revs but was 'fixed' with Ametech restore stuff and a service.

2.5k sounds very reasonable although I hope he hangs on for at least a year before that needs to happen... I've already burned through the new 944 slush fund. If the issues persist I may take a trip up to EMC as I've got relatives near to brum.

Fingers crossed for the MOT in a months time.

BTW... got the sunroof fixed this morning. Really easy job to change the gears and sync everything back up. To my surprise the sunroof motor clutch torque was already under 5nm so I left it as-is.

JamesO · Jul 17, 2011

As far as flushing goes, all I ever do is two oil changes in a row.
I have heard of people adding ATF (power steering fluid) to the oil for a brief spell as it acts as a detergent.
I would be surprised if the Ametech stuff would do anything but thicken the oil.

You can check for soft lifters without pulling the cams by taking the cam cover off, push the lifters down with a blunt screwdriver (when the cams point up). Rotate the engine by hand and check them all. Using that method I was able to find two soft lifters pretty quickly.

I have removed and re-fitted the cams without the tool, but it is very easy to strip the heads on the bolts.

robdimond · Jul 17, 2011

Thanks for the advice. I'll try an oil change first and if the noise persists have a poke under the cam cover.
I suppose the special tool doesn't really make much difference to the risk of stripping the heads as you still need to crack them loose. They are triple square if I remember correctly?
I presume you replaced the soft lifters rather than just cleaning them?

Any thoughts on the occasional lumpy running when idle and at low revs when hot? I've seen many possible causes on here to check out:

- vacuum leak
- fuel pressure regulator (been replaced in this cars life before 100k ago)
- coolant temperature sensor (the dash gauge sits on the first white line when warmed up, is this normal?)
- broken valve spring
- bad compression
- plugs, leads, distributor rotor/cap