Oil leak

[Ray Kinghorn]

The oil leak on my C4 has got worse recently - the car has done only 84k and feels really strong so I don't feel a full top-end overhaul is necessary, was thinking about having the engine out and the cylinder/crankcase seals replaced. Anyone else had that done?

 

[iangray100]

You will find if the engines coming out just to replace the " seals" as you put it ..that the time to get to the "seals" and disassemble the engine will also warrant replacing bottom bearing shells and taking on a top and boot rebuild ...I have heard of stories, as I brought the parts off the guy were he spent a fortune on the top end rebuild, and 5000miles later the bottom went .......basically a waste of money . If your going in to the fix a leak, you might as well the job probably as these cars aren't getting any younger in miles or years and it far easier to fix a ruining engine then one that has major damage inside!! When i had my engine a parts bearings were coming to the end of there lives...but if I had followed your analogy the engine pulled fine and ran ok ....so why did I both then? Personally I did it for long term reliability as I was starting to chase issues , so i nipped it in the bud !!!

 

[vitesse]

Ian, I have just read you postings & am very impressed as I would like to tackle this job on my 964 if & when it became necessary-at present no problems but at 106k miles likely in the future-however that is if it doesn't sell & I keep it. Could you give some indication of cost-say separately for the parts & operations and the special tools & sealants please? Cheers, Colin. As I own an engineering company,am a qualified mechanical engineer & have some experience of rebuilding engines,it's not too scary for me.[] However,that did not stop me making a fool of myself on the 993 section suggesting a way to adjust the bonnet latch-even though I have replaced one on the 964 some years ago-but had forgotten the type & from memory thought it was the traditional tapered pin type--doh[&o]

 

[iangray100]

Extract from my spread on the rebuild: 964 Porsche Engine Rebuild and Other Repairs : Expense Type Amount Parts Total £3,212.34 Nice to have parts while engine out £1,127.00 Air con parts £390.63 Tiptronic gearbox parts £99.00 Consumables £312.46 Engine Service.machining total £950.00 Extra service ( tracking) £55.00 Special Tools Total £1,017.08 Tax, P&P £367.01 SPENT TOTAL £7,163.51

 

[vitesse]

Ian, Thanks for that-not an exercise for the faint hearted clearly but a wonderful way to get to understand the engine. Cheers, Colin.

 

[Ray Kinghorn]

Thanks, all good advice and I was expecting someting similar anyway (although probably hoping that there might be a less expensive solution!!) Ray

 

[38F3E1]

ORIGINAL: Ray Kinghorn The oil leak on my C4 has got worse recently - the car has done only 84k and feels really strong so I don't feel a full top-end overhaul is necessary, was thinking about having the engine out and the cylinder/crankcase seals replaced. Anyone else had that done?

If the leak is really caused by the cylinder to case seals then the parts for these are only a couple of quid each but unfortunately you have to remove the engine and strip the top end to replace. Then when you have put new seals in rebuild the top end and refit the engine. The labour for this will be a large part of the 50+ hours usually quoted for a top end refurb of which 10 minutes is replacing the actual seals. As you can see a large part of a top end engine refurb is the hours required so once you are in there it makes sense to actually refurb the top end and then of course when you are in there it makes sense to open the case and do the bottom end if you are anywhere near 120K plus. Never has such a cheap part resulted in such a large bill to replace! As an FYI when I bought my 964 at 70K it had this exact problem. The rest of the car was so good it was worth it. I then did 40K odd miles on it without fixing the problem. As long as the leak doesn't get too bad and you don't mind drops on the garage floor and topping up the oil each month it seems to be containable. My logic was to do them when the engine was rebuilt. The only thing it limited me with was that I wasn't comfortable doing track days in it in that state because of the fire risk. Ian.

 

[Steve Brookes]

I think there are some good opinions here and as one who is about to embark on such a project I thought I would offer my own opinion. I should start by saying that I haven't got the ability or facilities to take an engine out myself so mine is going in to a specialist to have all the leaks fixed. On last inspection they advised me it is time for it to be done especially since mine goes on track and therefore it would be wise to have a dry engine for the reason Ian mentions. While the engine is out there will be a few other bits done like replacing tins that I've not been able to do while the engine is in, a new starter motor, a gearbox leak fixed, a new clutch hose and probably clutch slave. Of course, the state of the top end will be examined and overhauled if necessary. The while they're in there will be a new clutch and flywheel (RS lightweight of course!). I have a good idea of what this will all cost and it's going to be far from insignificant! I've also factored in to my estimate that other items will no doubt crop up. However, if the 'while they're in there' was extended to overhauling the bottom end then I believe that cost would double. I just don't have that much to throw at the car at the moment. So for me an engine out job to fix leaks is a worthwhile exercise and we don't necessarily have to get carried away by doing everything else while were at it. Now I just have to worry if I can get it done before the VAT goes up! []

 

[Alexander_Drobik]

hmm - my thoughts on this as it is something I went through this many years ago. You will be between £6k-£8k if lucky. Doing a top half is a false economy - apart from knowing you have an old lower half, the increase in load from a new top half could well accelerate matters. On the lower part, new shell bearings are a must. A crank re polish may be useful - low cost item - re polish not regrind mind. A look at the oil pump is also worth doing although with luck that will be ok. Pistons should be ok, but you may have a score on the camshaft in my case some scoring on one lobe of one crank - result two new crankshafts. Anyway you get the picture - you will be amazed by the number of springs, seals, nuts and bolts that also get renewed. On the barrel leaks - if yours is a late 92/93 car then the gaskets will be needed, if a pre-gasket car then the cost goes up a lot if you want the gasket done - better to by a recon engine than go that route. On my pre-gasket C4 I elected to keep the gasketless set-up, not many ever leaked and the trick seems to be to grind-in the barrels a little (as you do with valves) and apply some gasket goo - then tighten correctly. Mine is now 5 years on, plus loads of track days and with a motec conversion - no oil leaks etc. So it can be done. The upside - once done you have a very sweet engine, the downside is it could cost 30-40% of what the car is worth. Something to do if you are keeping the car imho. Hope this helps. Cheers

 

[Steve Brookes]

Since the original question asked if it was worth having the engine taken out to fix leaks, I disagree that this would be false economy just to do this. An engine can be nice and strong but leaky. My own is in that category. While leaky is not necessarily bad, the side effect of oil dripping on the exhaust and causing smoke is to my mind a good reason for getting the leaks fixed. A smoking Porsche in traffic jams is embaressing to say the least! Not everyone can say "seeing as it's going to cost me circa £3K to have the leaks fixed, I might aswell spend £6K to £8K to have the engine overhauled while I'm at it".

 

[Crystal Cranks]

I thought that the general consensus was that the bottom end of these blocks were nearly bomb proof and good for about 200k, are we all on the slippery slope of the while your in there syndrome? My engine was given a top end rebuild by Barry at Hartech @ 91k and I would have thought that if he felt the bottom end needed doing he would have done it and i bow to his better knowledge.

 

[Alexander_Drobik]

point taken but whilst the bottom end is generally bombproof but that does not mean it does not wear, and issues have been known - I can't recall exactly but one of the things typically found is wear on one of the bearings (is it No5 - need to look it up) and the odd crank has snapped. And depends a little on how it has been used/maintained etc. I guess it is what you want to live with, my point is that when the seals go (rubber degrades after 12 years or so), leaks start, valve wear is present and so on, you either cure it all or leave it alone. Both are fine strategies but I do think to do only half has risks. Either way you can see a big bill when you start opening the engine up - top-end, bottom-end or all. Good luck!

 

[chrism964]

I'm in this sorry situation too. Lots of oil leaks from everywhere (timing cover, powersteering casing, rocker covers, and the base of cylinders 1,3 to name just some {anywhere there is a gasket I think basically!}) but an engine that still appears to go ok. I could get all but the cylinder leaks repaired for around £1500 , a top-end rebuild for ~£2500 (depending on parts) or the full engine rebuild for between £3500 - £5500 depending on what's found when it's pulled apart. my understanding is that once the top end is stripped right down it's only a few hours more labour to crack open the bottom end and see what's going on. I think whether you go for a top-end only or a full engine rebuild is a personal and financial choice. There is no right or wrong. I generally think if I job needs doing it needs doing properly and ,in my opinion, this means looking at the whole engine (top and bottom) and replacing all the wear items (as necessary). I am also going to take the opportunity to replace any rubber hose/oil pipe/powersteering pipe/fuel pipe when this is done. I can barely afford to do this but it's what I feel should be done.

 

[appletonn]

ORIGINAL: chrism964 I'm in this sorry situation too. Lots of oil leaks from everywhere (timing cover, powersteering casing, rocker covers, and the base of cylinders 1,3 to name just some {anywhere there is a gasket I think basically!}) but an engine that still appears to go ok. I could get all but the cylinder leaks repaired for around £1500 , a top-end rebuild for ~£2500 (depending on parts) or the full engine rebuild for between £3500 - £5500 depending on what's found when it's pulled apart. my understanding is that once the top end is stripped right down it's only a few hours more labour to crack open the bottom end and see what's going on. I think whether you go for a top-end only or a full engine rebuild is a personal and financial choice. There is no right or wrong. I generally think if I job needs doing it needs doing properly and ,in my opinion, this means looking at the whole engine (top and bottom) and replacing all the wear items (as necessary). I am also going to take the opportunity to replace any rubber hose/oil pipe/powersteering pipe/fuel pipe when this is done. I can barely afford to do this but it's what I feel should be done.

I think you might want to add around £1k to the top end and full rebuild costs... Don't ask me how I know [8|][]

 

[chrism964]

ORIGINAL: appletonn I think you might want to add around £1k to the top end and full rebuild costs... Don't ask me how I know [8|][]

I'll let everyone know what the bill (and breakdown of costs) is when it's done. The quote (between £3500-£4500 for a 'straight forward' rebuild) is honest and from someone I trust. Obviously the price will depend on what is needed or worn out at the time. You can't take it with you!