Please someone tell me it's not true..again..

[Axl Rose]

Just been under the bonnet and found out that there's been some radical changes to oil filler since i last checked it about a week ago or even less(when it was completely dry)..
There's no sign of coolant on oil dipstick or noticable coolant loss yet but the engine is getting hot faster than before..it looks like the radiator incident might have damaged the engine after all..what i can't understand is why does it always happen to me..very sad now..don't quite know what to think..[]

 

[peanut]

don't panic it may just be some residue in the block that is gradually making its way out. It doesn't look a lot . I would just wipe it clean and monitor everything. If you were losing a significant amount of water then yes you would be right to worry but you say you arn't .

You could always get the local garage to do a leakdown test. Shouldn't cost much if anything and might confirm things !
Whats the history ? did you have a H/G failure ?

 

[Axl Rose]

No head gasket failure as far as i know..i've got a comprehensive pile of invoices and old MOTs..several service invoices describing the car as "very good condition for age"..
It seems to me that the troubles started after Silverstone Classic "parade" laps..i don't have chance to take the car on track very often(at all) so i pushed it a bit more than usual..so the next day after leaving Silverstone i broke down because radiator failed - i just noticed at one point that temp gauge was on max and pulled over..found out that all the antifreeze had leaked out and when i tried to top it up with water it came out as fast as it went in..so fetched the car back home on recovery truck..changed radiator the same day and had a 350 mile trip next morning with no problems..then just 2 weeks ago got stuck in traffic on M1 and the fan was constantly on..just less than a mile after i came off M1 i heard a big bang and then engine cut off..pulled over and found out that the rubber bushes had failed to hold radiator in place - the top end had fallen backwards so cooling fan came in contact with water pump > radiator hose and rubbed it until it gave up..so i patched it up and replaced the next day..but ever since this trail of misfortune i have noticed that it only takes a few miles for temp gauge to reach 1/4 and the "normal" temp is somewhere around 1/2..

 

[zcacogp]

The fact that you lost all the water and subsequently managed 350 miles in one go without problems would suggest you are OK from that one.

The temperature gauge going to 1/4 in a few miles, and settling around 1/2 is not wildly unusual, is it? Sounds pretty much like mine.

And that's not a lot of white sludge in the filler cap. It's no more than a trace.
A few short journeys can cause enough condensation to have this effect.

I know I am slightly paranoid about my P&J; can I suggest that perhaps yours needs a bit more driving and possibly a bit less worrying about?


Oli.

ETA: A compression test would identify a duff head gasket immediately. And would set your mind at rest. Well worth a try.

 

[peanut]

mmm good discription. My guess is that before these incidents your temperature would stay pretty much at 1/4 (lowest ) yes?. All three of my 944 would reach operating temperature quickly (within 3-5 minutes) thats the design because the engine runs more eficiciently at normal operating temperature. If the guage is normally at 1/2 way it shouldn't be a problem providing you keep a careful eye on it . I personally find it worrying when the guage runs that high normally. There is a special rated thermostat with a setting for cold climates that operate at 1/2 on the guage (ask me how I know groan )

Compression test won't tell you much in this instance as you are looking for a water leak rather than an air leak from the cylinders, so a leak down test would be more diagnostic. (Basically your coolant system is pressurized and checked over a period of time for pressure loss.) If you are gradually losing pressure in your coolant system the water will boil at a lower temperature.

I would be tempted to check all the coolant syatem hoses and possibly renew clamps where suspect , at least go round and retighten all hose clamps. It might pay you to connect a short piece of hose say 1 meter and raise it above the car when you refill the syatem . It should help to eliminate air . 944 are notoriously difficult to bleed correctly.Theres a tech file on it somewhere ,maybe Clarkes Garage or Pelican
heres a useful link
http://www.clarks-garage.com/

looking on the worse side the overheating incident may have caused your water pump impellor to become loose on the pump spindle

 

[Axl Rose]

Temperature was around 1/4 in normal town driving and i before these incidents i can't really remember it going over 1/2 even when stuck in traffic(exept when i warmed engine up on idle for testing)..driving on motorway - well..below 1/4 it usually were..[8|]..and i was quite used to it..ENGINE NORMAL OPERATING TEMPERATURE..that's a bit funny now..i have never really thought about it..what is the normal operating temperature for early '85 944 2.5 8V? And how do you know about that special rated thermostat?[] I've just started taking the Zermatt Silver car to bits - it didn't have a thermostat at all!! What's an impellor(i'm still learning)?[8|]


Just been in a garage but they were so "busy" that they didn't have time to have a look today..so we just had a 10 minute chat..answers considered -
a) some engines like to get hot;
b) the old thermostat might have been permanently open(actually i tested the old thermostat in boiling water - it didn't open at all..but i might have damaged it in removal process);
c) the mayo in oil filler could be just condensation..

Ok..cheered me up a bit to be honest..

Now the facts after i've been thinking and browsing around:

NOT ONLY IS THE NOT SITTING TIGHT IN THE HOUSING..IT'S THE NEW TYPE THERMOSTAT(FOR NEW WATER PUMP) AND IT'S OPENING TEMPERATURE IS 87c INSTEAD THE 83c USED WITH THE OLD TYPE PUMP..now that sounds like a pretty good reason to me..

Bought an antifreeze/coolant tester today..and found out that the antifreeze is quite weak as well..somewhere between -19c and -21c..that i'm sure plays it part..



Already phoned Sheffield OPC this morning and ordered a new thermostat+gaskets..due to bank holiday weekend will expect delivery next wed-thur..plenty of time to shop around for antifreeze..


But as it is nice and sunny today i will make myself useful and go check all them hoses

 

[Fen]

Thermostats are a consumable. In modern cars if your temperature isn't rock solid then you need a thermostat. The 944 is a bit older so as I posted earlier the gauge can move a bit before the fan kicks in but it should not drop when you drive fast and rise when you slow down very much. Dropping when you drive fast is a sure sign the thermostat has failed (I assume they are designed to fail open so as not to cause overheating).

As an example my appliance used to take ages to warm at all on my commute which is pretty much dual carriageway and motorway after the first 2/3 mile and never really got warm until I came off the M5. One new thermostat later and it's showing a healthy 90 degrees or so within 5 dual carriageway miles (and it's a diesel which warms up slower remember).

I've replaced the thermostat in most of the cars I have had recently - in fact only a couple in the past 5 years haven't had one that I can think of.

 

[Axl Rose]

That makes sense - my neighbor doesn't though..he told me to take the thermostat out and leave it out..as far as he's concerned the thermostat is only there to make your heater blow hot air faster so you wouldn't get cold in car around christmas time..oh well - he drives a 13 year old 1.3 diesel corsa that looks worse than my bin from in-and outside and would fail test with at leats 25 reasons..so i don't think i'm gonna take his advice...

 

[Hilux]

The thermostat`s role is primarily to allow a quick engine warm up and provision in recent years for the heater to operate quicker. Once hot it opens and allows a flow of water however this flow is still restricted to a degree by the `stat. Removing it frees up the flow so much that your pump and system can fail to shift the water quick enough (hot spots) or move it too quick (cool engine not ideal)

 

[Fen]

I disagree - It closes during normal operation to prevent coolant from passing through the radiator when it is not hot enough to need cooling. How else can the fact cars run cooler with a thermostat fitted but failed than a new thermostat be explained?

 

[Hilux]

Moot point Fen

A stat is closed initially so that the engine has a closed loop seperated from the main cooling run when the water is cold.It then OPENS and subsequently varies the flow (size of opening) according to the water temp.

A stat can stick anywhere in its scale of movement, closed so it never opens or open so it never closes (as did mine on the 951when it stuck towards the closed side as it was fine at speed but overheated on the cool (sic) down lap) or in its optimum open position which will also make the car run cooler at speed or hotter at idle without overheating to excess.

I did state in my post that without one the flow will be altered ergo the lack of movement to regulate the water temp will cause over cooling or over heating.

 

[Fen]

What I was primarily disagreeing with was the assertion that the primary function is quick warm up. I believe the primary function is to obtain and then maintain ideal operating temperature for the engine. In fact I think the maintenance of ideal operating temperature is key and the quick warm up is more happy coincidence than design aim.

 

[Axl Rose]

He's just one of these blokes(my neighbour) who likes to think that he knows the best solution for everything..his mate just came over about an hour ago - his rover turbo was misfiring and lacking power..popped bonnet - didn't take long to figure out that the AFM relay is on it's last breath..that's that then..but no - he still thought that maybe it's gonna make things work again if he changes spark plugs..


btw..they're still out there..

i'm off to Bon Jovi now..

 

[dlknight]

Thermostats are a consumable. In modern cars if your temperature isn't rock solid then you need a thermostat. The 944 is a bit older so as I posted earlier the gauge can move a bit before the fan kicks in but it should not drop when you drive fast and rise when you slow down very much. Dropping when you drive fast is a sure sign the thermostat has failed (I assume they are designed to fail open so as not to cause overheating).

As an example my appliance used to take ages to warm at all on my commute which is pretty much dual carriageway and motorway after the first 2/3 mile and never really got warm until I came off the M5. One new thermostat later and it's showing a healthy 90 degrees or so within 5 dual carriageway miles (and it's a diesel which warms up slower remember).

I've replaced the thermostat in most of the cars I have had recently - in fact only a couple in the past 5 years haven't had one that I can think of.

Hey Fen,

Looks like my first job on the turbo then mine seems to be pretty low on the temp guage when on motorway but warms up in traffic...

Dave K.

 

[George Elliott]

I replaced my 2 stats when I replaced the waterpump (preventative as I was doing the belts), the results were consistent with Fen's comments.
I concluded they fail open-flow (safe). You can test 'em in the kettle.[]
Previous temp needle was mid-way between 2 lower white lines, now its 1mm above the upper of the two lines. In traffic it hardly moves now.

George

944t

 

[Neil Haughey]

Years ago I had a thermostat fail in my Mini and it made it almost impossible to drive the car. Everytime I came to a roundabout the thing was way to cold and would want to stall so I ended up driving around with the choke on.

ISTR somebody saying the thermostat lasts about 2 years. I am not to sure about this perhaps a bit longer since I have only replaced mine once in 6-7 years.

It can be a PITA getting the thermostat in but I found it OK with the right bent nose circlip pliers and some form of mirror to see the thing. Vital to get it seated properly with the seal pushed into place otherwise it just lets water past the seal.

 

[Axl Rose]

It looks like that it was a false alarm - wiped the oil filler neck and just did over 50 miles today - it's still dry..no sign of water..altough it still seems to be running a higher temperature than i've been used to so far..in normal traffic the gauge stays in middle or just a tiny bit below but goes up to 3/4 pretty quick at traffic lights/slow traffic etc..hoping to put this on the wrong thermostat/gasket and weak antifreeze mix..should find out this weekend..

 

[Hilux]

Ensure its not got an air pocket, bleed the water system again.

 

[xenon]

Don't see how the concentration (or lack of) anti-freeze solution would make much difference. The specific heat capacity of water is slightly better than ethylene glycol and therefor pure water would be a better absolute coolant than an anti-freeze mix. Of course, your engine would corrode badly and freeze in the winter...

I think you have a thermostat / air-lock issue.

 

[Axl Rose]

Soon to be found out - in process of doing belts and tensioners..