This is the end, beautiful friend - oil checked

[Indi9xx]

Sounds like a classic number 2 rod bearing failure, in particular the loss of oil pressure following hard braking. A lot of people put it down to cornering, but I have for a long time thought the real problem occurs before the corner during braking and is only noticed after exiting the corner. I will keep my fingers crossed for you that even if it is the number 2 bearing, that none of the debris was thrown into the number 2 bore and has picked up between the bore and piston. Chin up, at least you didnt have a different kind of bad luck that comes with an armco bill.

 

[edh]

A tune for our older listeners there...and the song that was playing in my head on the way back from Spa []

I had a sudden loss of oil pressure braking for Rivage, stopped to check i wasn't losing oil & limped it back to the pits via a service road. There were lots of nasty noises at this stage and 1-2 bar of oil pressure.

In the paddock we checked the obvious stuff - crank pulley tight, OPRV not stuck - neither helped. We suspected that the oil pickup had fractured so tried overfilling the sump. immediately the oil pressure recovered to 3 bar at idle. The noises were very tappety top end noises, and didn't get much better.

That was the end of the track day, but as the car still seemed OK we decided to drive it back to the UK. There's no loss in performance, and you can't hear the noises once you're past 3k rpm. [&:]

I took off the cam cover yesterday and couldn't see any obvious damage. Most of the tappets felt a bit soft though - quite easy to depress. First time I've ever looked at them so have nothing to compare with. I tried some hydraulic lifter fluid but that's had no effect.

Nasty Noises

So I have 2 jobs to do

1. Fix the top end - remove belts, cams and replace faulty lifters (I hope that's it). If it's fixed I can then..

2. Remove crossmember sump etc.. and fix oil pickup. Plus the "while you're in there" inspection and probably replace the rod bearings as they have done 235k, and have had a couple of low oil pressure moment recently. Engine mounts also a good idea.

I don't want to sink a lot of money into an engine rebuild on an old car, particularly one that would break for much more than it would sell for whole already. It would be easy to get sucked in to headgasket, head refresh, crank scrapers etc.. but I'm not going there.

I guess if you had to pick a place to go, Spa is a pretty good one...

 

[edh]

If it was bottom end, would the oil pressure have recovered so well? And would it have survived a 450 mile motorway journey back?

 

[Indi9xx]

There are a couple of failure modes for number two.. spun or not spun. If the bearing spins you tend to get BIG bottom end knocks until eventually the con rod welds and breaks! If the bearing has not spun, often as soon as the foam/air lock clears you get oil pressure back, albeit lower than before, also if it has not spun, typically you do not get a classic bottom end knock, but something that sounds like a worn out cam, a hollow top end nock, which often turns out to be the piston kissing the head as the worn bearing effectively increases the stroke when the piston is not under load... In these cases often the noise might even come and go at idle, and sometimes will vanish under load, sometimes coming back at set RPM and load combinations. The good news, is in a non spun bearing, often the bore is undamaged and the crank is recoverable.

 

[edh]

Thanks jon. I still think there is a pickup problem as the oil pressure recovered immediately we overfilled it. This was probably 30 mins after the incident. I won't have any time to look at the bottom end for a couple of of weeks. Quite a big job to get the sump off on stands in the garage.

 

[Indi9xx]

One thing I have seen a few times is the oil pickup cracking where the tube is welded to the flange which bolts up inside the block, but usually this has gone hand in hand with a car which at some point had a bad ballance shaft belt by some crazy place. Unusual as you said that oil pressure improved after overfilling with oil.. but where the tube normally cracks would mean you would have to put a massive amount of extra oil in to submerge the crack... But who knows, maybe you will find a crack

 

[edh]

It's a question of where to start. It would be very frustrating to fix the bottom end only to find the top end is unrecoverable. It's certainly much more sensible economically to to dismantle the car for parts. 235k miles is pretty good lifespan.

 

[pauljmcnulty]

Stop talking about cars, this thread is about the Doors! Gutted, after all the problems at Bedford it seemed sorted. With my rational head on, and I know it's easy to comment if it's not my car, or my wallet, but nearly 250K miles isn't bad on an engine and I guess there comes a point where stressing parts so highly on track will find the weak points. Are you going to be fixing one thing, only for the next-weakest to fail? Would it be a more economical plan to fit a new engine, although decent used 16v engines aren't exactly overloading Ebay's servers. [&o]

 

[Indi9xx]

I think I would drop the oil and strain it through an old set of tights if you have an other half, or a new set if you dont Take off the oil filter and cut it open. Report what you find. Essentially, there is nothing in the top end which should destroy your oil pressure, so one way or another, the sump needs to come off anyway. What are you sills like? If they are good, I would say it is well worth replacing the engine with a used one or rebuilding yours.. If your sills are rotten, or the car has rot taking hold... its maybe time for the car to be retired. Would be a shame to throw away a solid shell though, no matter what the miles are.

 

[J.C944TurboMan]

Edh , there is a nice low mileage S2 engine on ebay now selling for £500-600 , this might be a cheaper option ?

 

[MarkK]

Lovely car!Just fix it!

 

[edh]

I just don't know how much more money I want to throw at this car - specially with a Boxster S with brand new m030 suspension waiting for its first track day... Ebay engines don't fill me with confidence - they are all low miles, great condition etc.. [8|] Having said that, the good bits on my engine (virtually new cams, new water pump, etc..) might sell for more than a complete lump would cost me. My car has loads of great parts on it - would break for £5k, which has to be the pragmatic option. The shell isn't bad now, but will never be rust free. It lived on the south coast & I've had one sill & the rear suspension mount rebuilt. I will check the oil next week & go from there.

 

[924nutter]

Ed I left bedford due to lack of rear tread before you left the second trail of oil. Bad luck there mate! I am not as conversant with the vaguaries of the 944 as Jon, but if I apply some simple logic, I cant completely accept the piston kissing the head theory. My reasoning goes like this; with wear limits on most white metal bearings being something like 4 thou or point 1 of a millimeter, I simply cant see an engine being designed with so little deck height clearance such that a perfectly serviceable engine simply on its wear limit would be at risk of piston clash but I have an open mind, and I am prepared to be enlightened; abject failure of the bearing is a different story, I had that on a tuned beetle which threw the rod but then again I was going "indicator repeater in the speedo" miles an hour (the scale didn't go around that far), and the first warning was tappet noise because the piston had already clashed with a valve and bent a pushrod. It would mean better than 4 thou tolerances between centres of the rod bearings when new or there would be problems from the outset. Furthermore any engine that has made its way back from Spa can't have too much wrong with it, though clearly from the sound something is amiss, but as I have said, I am no 944 specialist. My halcyon days were the days when breakerless ingintion was borderline science fiction, and the S U carb was a "piece of apparatus scientifically designed to deliver the wrong fuel/air mixture to the engines under all conditions and loads, that said, it comes very close" [This is almost verbatim from the lecturer on SU carbs] The engine is going to have to come out to investigate the original cause of the loss of pressure so get the specs and measure the crank journals befofre you decide the route you are going to take. I would put money on the journals of the 944 crank being at least as hard as the ones on the 924 and after 180 thousand miles of abuse my local engineering workshop could find no ovality on the crank of my 924, just as long as the journals aren't scored, then its a different ball game. I would like to think that 3 bar should have been enough to pump the tappets back up on the run back from Spa but perhaps not, especially if as you say there are a couple of soft ones. Apart from the loss of pressure mystery, the main unknown is how much swarf (if any) has gone into the sump, been picked up by the pump and circulated to the rest of the engine. Like Jon says, cut open the filter, but even with the best will in the world if ,IF, there was any swarf, due to the centrifugal force at the big end cap, it is inevitable that some swarf contaminated oil will not have been strained out by the filter, but all is conjecture until you get the lump out and "get the lid off". I am just saying do not fear the worst until you can prove it. Of course there is always the 250k mile argument to be considered, and I see you being in that horrible place between "sod it i've had enough of fixing this, "It'll part out for more than the cars worth with a crap engine" and " I love my 944" Good luck

 

[DarrylH]

Sorry to hear about your problems but found this photo on another forum of it []

 

[edh]

Ha! just saw that on facebook an hour ago. just going out for some instruction with Martin from the Burgstube

 

[MarkK]

Got me thinking about Goulash and Bittburger now!!

 

[MarkK]

Please fix it!that car needs to live!!! Looked so good the other day on the M1! Its sort of a race car,they never make sense financially...!

 

[Indi9xx]

My first experience of a big end going was as an apprentice when I blew the big ends on my Ford Capri 2.0 pinto engine, which had the usual low deep knock, especially at around 2000 rpm... Then when friends experienced the same failure on other cars I got used to the noise. The same car developed a flat spot on its camshaft, which made the typical higher up hollow clack clack noise. The first time I heard a big end go on a 944, I was sure it was a camshaft, even though my father, who I was a trainee under, told me categorically it was a big end, which I did not believe, until the head came off... No damage to the head, but the squish lands on the head had been lightly hammered with matching burrs on the head and piston on number 2. Since then I have seen the same happen a lot of times.. Its not something I see every week, month or even every year.. Usually the engines are really durable.. But I think the last one we heard with big ends gone, yet making a nasty top end noise was a member from here's car. From memory, the S2 head gasket has an uninstalled thickness of 1.4mm (measuered on the fibre edge), which closes up to a head to block deck thickness of 1.2mm under compression when installed, which is a massive amount of wear or damage that a rod bearing needs to sustain and still run, but then again I have seen a carrillo rod which had a damaged end cap because a 944 crank had eaten through the bearing and into the end cap.. But that was one seriously trashed engine built by a turkey! The mad thing is the amount of rod bearing wear/damage there can be and some oil pressure still remaining. Can't wait to find out what is found once the sump is off

 

[u63af]

Ed, I have a good complete low mileage bottom end which is due me about £200. I had to break a complete car to get it. If u don't want to sort it then let me know. I may be looking for a project car. Email me sandyfaloner@hotmail.co.uk

 

[Andy97]

Have you spoken to PH? He may have something available and if he hasn't he'll know someone that has.