Sadlotus

Hi all.
Always wanted a 944, but they've always been too expensive or I've been too poor.
Bought myself a 944 turbo last week - 238 thousand miles. It's a bit like Trigger's broom - everything seems to have been replaced. Black with White linen interior, toolkit, blind, pump, non cracked dash, clock works (but no light!), on it's second service book, 3" thick history. A truly no expense spared car.

But.

Showing off to my son 'WOOHOO! POP! POP! TINKLE TINKLE! mmmmm......
Get back home and a puff of white smoke means either one of two things - the exhaust got a good clearout of condesation (unlikely after a two hour drive to my son's to get out of London) or.. head gasket....
Drove for another hour before the guage went north and I had to stop. Lots mayo in the filler tube ......Bloody.

Question 1: Why did it go?

I'm going to do it half and half with a local racing prep garage.
Me: 'I'm a little scared',
Raceshop: 'Why?' I't's an engine.
Me: 'True, I've rebuilt Lotus Twin Cams and bike engines before.... but there's a lot of pipework!'
Raceshop: 'Don't worry.'

Question 2: What should I look for?

Looking through the history I now see the engine was rebuilt two years ago in 04/2014 (10k miles ago) then head repaired one year ago in 04/2015 after the cambelt broke! (by the Specialist Porsche Company that did all the PO's work!)

Question 3. The car has a Promax Level 2 Performance Kit on it. (The PO made no mention of this)
(http://www.promaxmotorsport.co.uk/pr...mance-kit.aspx)
Could this have been a contributing factor?

Question 4. what are the two unconnected pipes just behind the airbox in the picture for?

FYI. It ran for two hours through London rush hour traffic with no overheating issues whatsoever.

Thanks for reading - suggestions.. and forebodings please.

Paul

Paul Waterloo

If it's anything like the MK1 996's the heads crack and then you get intermix with your coolant, first warning is a low coolant light, then you check the expansion tank and you have a milkshake in there.

You said it had the head repaired a few years ago, I do not know common issues with the 951 engine, but I would not be surprised if that repair failed or wasn't repaired correctly in the first place. Sorry to hear.

Sadlotus

Thanks Paul - yes I'm hoping/guessing the head wasn't repaired properly the first time and it's not an underlying issue with my particular engine. The race shop suggested that the cambelt broke because it was too tight at engine rebuild time.
They said def a boost guage (although I'm reluctant to mess with the standard interior - underbonnet maybe) and def a rolling road session.

black944 turbo

The two disconnected hose go to the cycling valve. Most people bypass the cycling valve when a manual boost controller is installed. The hose from the intercoller pipe with the banjo bolt is what originally connected to one side, but probably goes to a manual boost controller now.

Jherriott

Mine blew the head gasket internally 16 years ago... no leaks outside, but cottage cheese inside. No biggie.

Sadlotus

Thanks Jason - reassuring.
Black944turbo - I've read that it's not a good idea to remove the Cycing Valve on a stock engine. (Still early ownership days) Mine's stock apart from the Promax Performance Kit. I need to talk to them and see what else they did.
Thanks all
I'll be back.

sherry66

Hi , the engines are easy to work on unless in the car where access is very , very limited.
Any problems with the head pm me as I have a freshly skimmed one stored in the loft if you need it ,Southampton based.
Simon

black944 turbo

If it has a pro max kit then it is chipped and it is very common to have the cycling valve bypassed at that point. You will need to verify what the chip is setup for and would want a boost gauge.

FRporscheman

Check the dipstick to see if the oil has water mixed with it (it will look like milkshake). Also check in the coolant tank.

If they're mixing, it could be the head gasket. This is where you say "it's just an engine" and use the usual diagnostics to figure out where it's leaking and then find a DIY procedure on how to mend it.

Assuming you'd do it yourself... as you take it apart, take pictures, and label everything. Yes, there's a huge mess of tubes, but it's still easier than working on a newer car.

Sadlotus

Update.
Yes the head gasket has blown. At the corner(?) of number 4.
Head is off to be checked for cracks etc - doesn't look like any valves bent.
But. The garage did a deck height check and the rod of number 4 looks as though it's bent.
That was Friday pm when they told me.
Any ideas why the HGs blow? It's just over a year old since it was last done.

Tom M'Guinn

Car looks great! Bent rod? How did the mechanic reach that conclusion? With a rebuilt motor in a 238k Tigger's Broom car, I'd want to confirm it's really the rod. If needed they should be able to replace it anyway.

As for the HG, these motor are touchy about that. Assuming head and deck are flat and smooth (make sure to check), studs are good and torqued properly, and a standard gasket was used --all big assumptions on a rebuild motor, especially if the guy who built it couldn't keep the cam belt from snapping-- then blown head gaskets are usually the result of detonation/knocking in these cars. Knock, in turn, is usually the result of some tuning issue -- i.e., some combination of being too lean on boost, too much boost, too little octane, too much ignition advance, etc. Your car has lots of unknowns in the tuning dept, with performance chips, unknown boost control, unknown boost level, unknown AFR, unknown knock count, etc.

Best bet to start would be to return it all to stock, and take it from there. Or, if you want more power, find someone familiar enough with these specific cars to set it up safely. If you modify it for more power, you'll want a boost gauge, wideband O2, and knock counter in my opinion. Or you can have it dyno tuned if your not the type to keep tinkering...

beamishnz

That is a great bit of advice. Not nice trying to second guess someone elses plumbing,

Was helping a friend recently who had just bought a Silver Rose who had a similar 'modified car' ... in this instance a jumble of Lindsey Racing components. Car ran when he bought it and then experienced starting problems. When it was stripped down the piston tops were thick with carbon (rich) and the rings were welded to the pistons and the bores were all scored badly (lean) so the mods had clearly screwed the tuning. Engine rebuilt, everything put back to stock and the car is running like a dream and feels just as fast as when in 'tuned mode'.

gruhsy

Sorry but don't you mean the tune didn't match the mods. One does not do engine mods without adjusting the tuning to match the modifications.

beamishnz

Absolutely the tune didn't match the mods and with someone elses mods absolutely no idea if it has been tuned correctly or even if it can be tuned correctly. All sorts of pipes detached ... fuel pressure regulator set super high ... just a mess. It is all too easy to fiddle with these cars and end up going backwards. I know there are some knowledgeable guys that have had great successes these are well documented on this forum ... but I've seen others where the' mods' were a disaster in terms of performance and longevity.

For the OP who has unknowingly acquired a modified motor that is blowing head gaskets it seems like a great bit of advice to get back to stock and then experiment from there if he wants to.

Ray Singh

Hello SadLotus.

Welcome. I am another UK citizen who is lurking here on Rennlist. It is a fantastic resource and there are some very helpful people here.
I am a turbo nut and have owned two turbos (250 and 220) and have recently bought a N/A 1985 car. I am struggling with it and bought it because i thought i couldnt afford a 944t. I am going to see a 944t tomorrow, so may have two 944s in my posession soon!

Keep us posted on yor car, it looks lovely.