Help - Losing water.

[Guest]

Very little mileage these days as it is used as a work car for my partner who has a 5 mile round trip to work and back.

She said she wasn't running (or starting) too well, and on checking everything over, the battery seems weak (the alternator tests fine), but I noticed the water was very (very) low, and it needed the best part of 3 litres to fill up.

There is no evidence of any leakage either on the engine or the driveway, so I have to assume that it's leaking into the engine somewhere?? This would explain the less than perfect running, and less than perfect starting, so I'm hopeful...
The water pump bearings are audible, so that is definitely an issue, but they are not leaking any water there.

Is there a list of more likely options ? Anyone any similar experiences?

Any help advice or pointers very much appreciated.

Andy

 

[geoff Ives]

Sorry about this but the chances are that the cylinder head gasket needs replacing. This is an inherant problem with the 924 and usually happens just after 100,000 miles. If you use a garage the cost will be about £400 as the head MUST be skimmed. This is the number one 'will happen' for the 924 but 100K miles before a problem isn't bad.
If you do the job yourself ... remember to get the head skimmed... it isn't optional!!

 

[vincematthews]

To check Geoff's suggestion -

For water into the oilways via the head gasket:
Are you getting water in the oil (mayonnaise type slush on the inside of the filler cap or water on the dipstick)?
Is the amount of "oil" increasing due to water being added? check the dipstick.
Water in the oil is A BAD IDEA so don't run the engine anymore than you have to or you may get more expensive damage (you probably know this?).

For water into the cylinders via the head gasket:
Are you getting white smoke/vapour out of the exhaust after the car has warmed up?

What do the oil pressure and water temperature gauges read?

Of academic interest, I believe the weakness on these engines is usually between cylinders 3 & 4 but is mainly because there is so little material between each cylinder bore on this engine.

You may find a second hand head is a cheaper option - as long as you can be sure it doesn't have the same problems . . .

 

[geoff Ives]

Sorry to sound argumentative but you shouldn't need another head. If it has been removed a second hand head would still require skimming. With yours you at least know that the valves are ok and when you take it to an engineering shop to have it skimmed they will advise you as to it's servicability.

 

[geoff Ives]

Just a thought. A leak under pressure from a joint or pinhole in a pipe would cause waterloss without leaving a trace as it would be hot and under pressure. It wouldn't cause the starting running problem however.

When our 924 lux blew it's gasket it started (just) but ran on 2 or 3 cylinders on slow speed (couldn't call it a tickover because it didn't.. Tick over) but ran better at speed.

 

[vincematthews]

Doesn't sound argumentative . . . maybe I didn't stress the "as long as you can be sure it doesn't have the same problems . . . " bit enough . . .[]

ORIGINAL: geoff ives

Sorry to sound argumentative but you shouldn't need another head. If it has been removed a second hand head would still require skimming. With yours you at least know that the valves are ok and when you take it to an engineering shop to have it skimmed they will advise you as to it's servicability.

 

[924nutter]

Guys, Guys, you are being way too pessimistic. The headgasket is likely to have blown in the 10 o'clock position of number 4 cylinder but providing the two gasket faces haven't fretted against the head, making a recess, then fitting a new gasket is perfectly satisfactory. I certanily didn't do it on either of my 931s or my 924s. I strongly recommend that when the head is removed it is checked for warping though. It is also entirely possible that the heater matrix has a leak, and over time the coolant has boiled off and the rough running is due to overheating, but that wouldn't explain the poor starting so I would plump for the head gasket. Before ripping it apart, do a compression test, the values should all be within 10 psi of each other at about 142 psi
Bear in mind that the stretch bolts on the n/a 924 are not reusable, but the bolts of the 931 are, so take that into account when budgeting for the job.

 

[924nutter]

I've been giving the idea about skimming the 924 cylinder head some more thought, and whilst it is desirable ( but not essential) on the normally aspirated engine prospective repairers of the 931 should consider the fact that there is a considerable sized combustion chamber in the Porsche designed head and it is not for mucking about with. The capacity of the chamber will be reduced by skimming, and raise the compression ratio which Messers Porsche have spent so much time reducing to 8.0 or 8.5 to one depending on series, in order that the engine will tolerate 98 octane fuel without pinking. Unremedied, the pinking can lead to catastrophic piston failure. Skim the turbo head at your peril.

 

[geoff Ives]

Just a thought John. If the head of a 9311 needed skimming how about 2 gaskets? I have done that with motorcycles.

 

[924nutter]

Dont know if the 931 head will tolerate the removal of 2mm or 80 thou without making the material around the waterways dangerously thin. Anyone?