Victors Mutterings part 3

[Victor Meldrew]

After a very frustrating drive to Aberdoom last night where the car was happily overheating for no reason other than it hates me... I have come to the conclusion that as I have changed everything else its time to fit a new waterpump...

One sitting ready in the garage...

Also need to replace a camshaft oil seal as its making a mess on the drive and the missus is making a fuss...

So plan is, whip off the timing belt, change the pump, out with the cam and fit new seal...

Problem is, too sh*t to have a go myself even after watching the video on youtube and reading up about it so maybe its best to pop it over to Ali's....

[hiscot]

if its overheating without loosing water then yes maybe pump, or most likely a faulty thermo stat ( sticking shut ) but if your loosing water then over heating suspect a leak put a bleed easy on the exp tank and look for a leak under low pressure
however if you have oil on the cambelt change it ASAP they dont take to oil and it will fail , (i always change the pump at the same time ) again are you sure its a camshaft seal ? ( what side ) they can fail and you should be able to fit a seal with out removing the camshaft or its ladder but always find the cause of any fault before you go any further it saves grief later on
if your not sure in any way take it to Ali's it could save you a fortune

[robin]

Have you reverted to the standard thermostat layout since the PRT was fitted?

Does it overheat whilst stationary but running at increased engine speed, or only under load?

If it does overheat whilst stationary at increased engine speed, then It really really shouldn't be that hard to get to the bottom of this; by all means change the water pump, but unless you've proven it is the water pump I suspect you'll be wasting your time and money.

If it only overheats under load, then I very much doubt it's the water pump (the water pump cannot tell the difference between the engine under load and the engine running under no load at the same speed). It is still possible to be the water pump under these circumstances (perhaps because it has impaired performance due to some sort of wear, so cannot shift enough coolant to keep the engine cool) BUT you would be able to see that as low pressure at the bleed nipple on the return path.

Camshaft oil seal does not require removing the camshaft, but you do have to remove the cam pulley if the leak is at the front of the engine - however, without removing the cover how do you know it's a camshaft - it could also be the crankshaft oil seal.

If the oil leak is at the gearbox end of the engine, no need to dismantle anything much - pop off distributor if required, hoik out old seal, clean up and press in new nicely lubricated seal carefully to avoid damaging it, job done.

Cheers,
Robin

[Victor Meldrew]

Have you reverted to the standard thermostat layout since the PRT was fitted?
Back to standard with the layout.

Does it overheat whilst stationary but running at increased engine speed, or only under load?
It does overheat eventually after a sustained hammering at sustained high engine speeds, i.e back road bashing.. but when I drive it at 70mph, at approx 3k rpm it runs fine without any overheating issues. When I slow down and the revs drop much below 3k then the temperature imediatly starts to rise and quickly boils. If I change down and hold the revs above 3k then the temp returns to normal and this when I'm just trundling through a town so it isnt under heavy load..

If it does overheat whilst stationary at increased engine speed,
Whilst stationary at idle from cold it doesnt get much above 90 deg, it will run like this for hours.... (well half an hour with no change)

by all means change the water pump, but unless you've proven it is the water pump I suspect you'll be wasting your time and money.
I bought an uprated pump from Geary at the Lotus show at Donnington, so its sitting in the garage doing nothing just now.

It is still possible to be the water pump under these circumstances (perhaps because it has impaired performance due to some sort of wear, so cannot shift enough coolant to keep the engine cool)
Thats what I am thinking ..

BUT you would be able to see that as low pressure at the bleed nipple on the return path.
Would need the eye of an expert to tell me if what I am getting is normal or not..

Camshaft oil seal does not require removing the camshaft, how do you know it's a camshaft - it could also be the crankshaft oil seal.
Thankfully its cleary visible, and luckily on the non pulley end, exhaust cam which I can see..

If the oil leak is at the gearbox end of the engine, no need to dismantle anything much - pop off distributor if required, hoik out old seal, clean up and press in new nicely lubricated seal carefully to avoid damaging it, job done.
Now that I know it can be done without a strip down thats a bonus.. now whats the part number for a non VVC camshaft seal...?

Cheers,
Robin
Quality response as ever, thank mate.

[Rich H]

John,
Has the rad been changed? Could it be silted up and not cooling enough?

I have a PRRT fitted and apart form a temp that wanders about it very rarely gets hot enough to run the fan, it doesn't overheat stationary and the temp drops from 98+ after a drive then stopped in traffic to 90 in seconds once I start moving again.

Rich.

[Victor Meldrew]

John,
Has the rad been changed? Could it be silted up and not cooling enough?

I have a PRRT fitted and apart form a temp that wanders about it very rarely gets hot enough to run the fan, it doesn't overheat stationary and the temp drops from 98+ after a drive then stopped in traffic to 90 in seconds once I start moving again.

Rich.

New high capacity rad fitted last week, and a nice little bit of kit it is..

[Rich H]

I would be if it was working

Does it get hot all the way accross when the car overheats? Might be worth a check, if the pump is lazy it might not befroe the car overheats.

[Victor Meldrew]

I would be if it was working

Does it get hot all the way accross when the car overheats? Might be worth a check, if the pump is lazy it might not befroe the car overheats.

Its hard to tell, most of the time it hot all the way accross but then it boils and spews coolant and then airlocks.... spend 15mins bleeding through with the passenger side parked half way up a bank, and its all back to normal again..

I get no problems with for ages it until it boils the first time, then it needs bled through to get it back to normal followed by relevant fluid replacement...

I dont think its an airlock issue as it can run for hours without issue, been using it all week with two trips to Aberdeen and back with no problems, albeit at slightly more sedate pace as it was damp n greasy.... first extended dry run with it and it boils on slowing down after a quick section... keep the revs up and its fine...

[Rich H]

Small pressure leak then, the revs keep the pressure high enough when its v.hot (Not an issue when its not run so hard), but when the revs drop the pump output pressure drops a little and the coolant boils?

Heater matrix? Or is that bypassed?

[mac]

Over pressurise the system (engine off) with an easy bleed and a well inflated tyre and a liberal sprinkling of talc - or even some of that spray on talc at the joints?

[RDH]

John
just put a match to it and be done with it!


Happy birthday BTW

[Victor Meldrew]

[quote="Rich H"]Small pressure leak then, the revs keep the pressure high enough when its v.hot (Not an issue when its not run so hard), but when the revs drop the pump output pressure drops a little and the coolant boils?

Heater matrix? Or is that bypassed?[/quote]

Nope, not bypassed at the mo.. it was bypassed a while back but the problem was still there.. might try that again but its a good indicator if the heater starts blowing cold then there is air in the system...

[fd]

And you're as sure as the surest person who is very sure that they are sure that this isn't an HGF issue ?

Fd

[Rich H]

I suppose boil = gas in coolant = fire ring fail

[steve_weegie]

And you're as sure as the surest person who is very sure that they are sure that this isn't an HGF issue ?

Fd

I was pretty sure mine wasnt a HGF, but in my defence the first sniffer test was negative

I have a coolant sniffer if anyone needs it