Can anyone out there give me some advice on the time & level of difficulty involved in replacing the large O-ring at the base of the coolant crossover? I'd like to know if an owner such as myself with marginal mechanical skills can take this on. Does the entire intake manifold have to be removed to accomplish this (as my mechanic is telling me)?

I'd would just have him do it for me, but I've pretty much reached the end of my rope, as my car's been at his shop since the beginning of February, when it went in to find (among other things) a coolant leak that I couldn't trace. Today, after finally getting the engine back together following the head job (as justified by the leakdown test this winter), I'm told that it's leaking coolant from the above-noted O-ring and that he has to remove the intake to replace it.

Given that we have 5 decent driving months up here and I've already missed 3 of them, I'm getting a little stressed. I've made the decision that I simply can't afford the time without the car or the money to keep sending it to the shop and will have to start doing the relatively simple maintenance and repair work myself. Other than committing a justified homicide, does any one have any helpful advice?

 

Laird,

I need to do mine too.

The crossover CAN come off with the inlet manifold in place. A friend of mine had his off on his 1990 S4 without remoing the manifolds. The oil inlet bracket needs to be removed 1st (of course) and the nuts / bolts holding this on are apparently difficult to get at. But by no means impossible to do with ordinary non-specialised tools. (If you remove the inlet manifold then all the 'while you are in there' jobs will put the O-ring replacement into an entirely different price and time bracket).

Reading between the lines it seems that you're somewhat relucatant to 'bite the bullet' and start doing your own repair work. It was only when I plucked up enough courage to start doing things myself that I really started to enjoy ownership, rather then being scared of things going wrong. When all's said and done, it's only a car!!

I would think that the job you're talking about would be a good one to start the road to doing more work on the car yourself. Of course it helps enormously if another 928 owner or two pitch and and you do it and learn together. From my limited experience, the sort of job you're contemplating is not too difficult provided that 1. You are prepared to undo all the things necessary to get access - easier in the long run than leaving restrictive 'stuff' in the way 2. Think about the job before doing it, and get any advice (as indeed you are doing here) and 3. Tackle it slowly and methodically, documenting / photographing as you go. 4. Check, check, recheck and think about what you've done before starting it up after the job. (e.g did I get coolant water in the oil? Did I get water into any cylinders. Have I put the coolant back in - that sort of basic checklist stuff).

All the best

 

I've replaced these seals on my 90' S4, as part of the top end refresh.

The intake manifold comes off first. If you have leaks, you might have a problem with corrosion of the bolts where they go into the heads, making them difficult to remove.

Since the heads on your car were just removed and replaced, they must have replaced those gaskets and the rework should be under warranty.

The O-ring is simple to install using silicone grease as a lubricant, but it's only one gasket used in the reassembly.

So you might be better off having the shop do the work now rather than later.

 

Hello All,

I also did this when I had a broken breather hose. I didn't have to remove the intake manifold to remove the water manifold (coolant crossover). John Pritle had a great write up on the process.

Make sure you get all of the o-rings / seals:

Water manifold kit (3 o-rings)
Oil filler oring (big square)
Outer thermostat seal (large o-ring)
Inner thermostat seal (smaller metal/rubber seal that inserts inside the water manifold)
You might as well check/replace the breather hoses and clean the "V"

Here's the link to John's write up: http://members.rennlist.com/pirtle/svc_coolant.html

Good luck,
Roger 87s4

 

Have the shop fix their own problem. If you touch it, their entire work becomes your problem. Never turn someone else's problem into your own.....even though it is your own. Understand the difference?

 

Thanks for the quick responses. I went and exercised my visitation rights with the car this morning and had a good discussion with my mechanic.

Dave hit the nail on the head regarding doing work on my own. As much as I'd actually look forward to undertaking the task (especially with John's excellent step-by-step directions for the crossover removal - thanks, Roger), I'm going to heed Greg's advice and have the shop undertake this as part of the repair that they are already getting paid for. The fact that they were getting paid to find & repair the coolant leak lands this back as their responsibility. I'll settle for working on it during the winter months, when time is not at a premium. I know that there will still be a long list of items to be done then.

 

I've got to do this job next week. I replaced my oil filler gasket and a leaking hose from the breather, and in doing so (like an idiot), I forgot to replace the huge O-ring when I had the crossover removed. So when I fixed the oil leak, I caused a water leak. It isn't a bad job; it only took me a few hours to pull the crossover, fix the oil leak, and replace some other things under there as well.

 

Degree of difficulty varies quite a bit on this...IF you don't snap any bolts (steel bolts don't play well w/aluminum crossover) I would say it's a 5 hammer job (on a scale of 1-10 hammers). I did it a couple of years ago on my 82 5spd and did not have to pull the intake to get at it. In trying to get the 4 angled allen bolts out that connect the crossover to the block, one came out easy, the other 3 snapped. Quickly turned into a 20 hammer job (the angles were insane to try and get a drill, or any tool for that matter, onto the snapped heads...eventually had to dissolve the steel bolts out of their channels to get the crossover off)
Put it all back together and fired it up...and noticed the W/P was spraying water everywhere...embarked on the classic TB/WP adventure and now I'm dealing with a classic 'No-Start' because the car has run for about 20 minutes in the last 2 years!!!

On the bright side, I'm the only one that I've read about/talked to that has experienced this level of nightmare trying to replace the crossover O-ring, so if you do decide to tackle this one, take it slow and easy and get your wits about you when you tackle those angled allen bolts!!

Good Luck!