Cerbera overheating after looking for oil leak
Discussion
Hello all
Hopefully someone has an idea here as I seem to have a fault that is very coincidental...
I just had a whole pile of work done on the car (body off chassis refurbishment plus extra stuff). With the refurbishment the car has just had a new radiator core, new ACT hoses and stainless pipes. Also the temperature gauge has a new sender.
Post this I have done perhaps 400 miles.
When I got the car back I found I still have a small oil leak that seems to pool up somewhere and make a mess when you park up or drive away. This weekend a mate and I took the car for a short run to warm the oil up then jacked the car up at the front so we could see under it and then ran the engine while looking at the pipes on the sump etc. to see if we can spot where it was coming from.
The cooling fans cut in as expected but then I spotted that the temperature was up at near 110oC.
Once the pressure was safe to take the cap of the expansion tank I measured the water temperature with a real thermometer and it was within 10 degrees of the gauge, both close to 90oC, so it really is overheating badly. It takes about 5 minutes driving to be ready to boil.
The previous day there was no issue with temperature and at bumbling along speed registered 90-95oC.
I have bled the system on the radiator end bold (no air) and on the drivers side rail which seemed like it might have had some air. I blew into the expansion tank to force the fluid through.
I didn't do the passenger side as looking at the workshop manual I didn't realise there was a bleed there so that is one point to check.
USEFUL NOTE (I hope) – the bled valve is a left-hand thread as presumably it screws into the pipe with a right hand thread.
The front belt on the engine seems to just power the air con pump so I'm not sure where to look for the water pump.
QUESTION I presume the alternator and water pump are powered from the same belt. No idea as the only belt I can see powers the AC. Please enlighten me !!! The battery seems to be charging ergo I assume the belt is OK? As the battery voltage and the car is charging so does that mean the water pump is being driven and the impeller should be doing its thing?
Anything I've not checked before I replace the thermostat?
I guess if it is not the thermostat then it must be the pump?
Cheers
Wurgle
Hopefully someone has an idea here as I seem to have a fault that is very coincidental...
I just had a whole pile of work done on the car (body off chassis refurbishment plus extra stuff). With the refurbishment the car has just had a new radiator core, new ACT hoses and stainless pipes. Also the temperature gauge has a new sender.
Post this I have done perhaps 400 miles.
When I got the car back I found I still have a small oil leak that seems to pool up somewhere and make a mess when you park up or drive away. This weekend a mate and I took the car for a short run to warm the oil up then jacked the car up at the front so we could see under it and then ran the engine while looking at the pipes on the sump etc. to see if we can spot where it was coming from.
The cooling fans cut in as expected but then I spotted that the temperature was up at near 110oC.
Once the pressure was safe to take the cap of the expansion tank I measured the water temperature with a real thermometer and it was within 10 degrees of the gauge, both close to 90oC, so it really is overheating badly. It takes about 5 minutes driving to be ready to boil.
The previous day there was no issue with temperature and at bumbling along speed registered 90-95oC.
I have bled the system on the radiator end bold (no air) and on the drivers side rail which seemed like it might have had some air. I blew into the expansion tank to force the fluid through.
I didn't do the passenger side as looking at the workshop manual I didn't realise there was a bleed there so that is one point to check.
USEFUL NOTE (I hope) – the bled valve is a left-hand thread as presumably it screws into the pipe with a right hand thread.
The front belt on the engine seems to just power the air con pump so I'm not sure where to look for the water pump.
QUESTION I presume the alternator and water pump are powered from the same belt. No idea as the only belt I can see powers the AC. Please enlighten me !!! The battery seems to be charging ergo I assume the belt is OK? As the battery voltage and the car is charging so does that mean the water pump is being driven and the impeller should be doing its thing?
Anything I've not checked before I replace the thermostat?
I guess if it is not the thermostat then it must be the pump?
Cheers
Wurgle
The twin water pumps and oil pump are internal and are all powered from the auxiliary shaft that also runs the external power steering pump.
The later 4.5 engines (perhaps 99 onwards) apparently have a more robust aux shaft, as the earlier cars can suffer aux shaft failure. That is the worst case scenario, better options are faulty thermostat, blocked rad, air lock, even head gasket failure is less painful.
Despite your checks it is still possible that the dash temp guage is faulty, the only reliable way to check engine temp is via the diagnostics (such as Aide's App). Even then it is worth swapping out the temp sensor, as they can be faulty.
The later 4.5 engines (perhaps 99 onwards) apparently have a more robust aux shaft, as the earlier cars can suffer aux shaft failure. That is the worst case scenario, better options are faulty thermostat, blocked rad, air lock, even head gasket failure is less painful.
Despite your checks it is still possible that the dash temp guage is faulty, the only reliable way to check engine temp is via the diagnostics (such as Aide's App). Even then it is worth swapping out the temp sensor, as they can be faulty.
Moderately sure it really is overheating not the gauge – thermometer plus a infra red temperature sensor “gun” unit etc.
Oil leak drivers side air box – yes I think this IS leaking but its not the major leak. I think it was between the box and where the metal tube that the big return pipe connects to is fibreglassed into the box. Sorted this with silicon and also the oil is not on the F1 panel and so makes me think this a minor issue if it still exists...
Big issue is the cooling. Why has it suddenly stopped working... Anything to do with the maintenence or just bad luck...?
Oil leak drivers side air box – yes I think this IS leaking but its not the major leak. I think it was between the box and where the metal tube that the big return pipe connects to is fibreglassed into the box. Sorted this with silicon and also the oil is not on the F1 panel and so makes me think this a minor issue if it still exists...
Big issue is the cooling. Why has it suddenly stopped working... Anything to do with the maintenence or just bad luck...?
Have you been round every jubilee clip on every coolant pipe to nip them up, this needs doing if you had silicon hoses fitted?
If not then I think you may have lost some coolant and got an air lock as well, try bleeding the passenger side rail with the engine running, if fact start at the rad and work you way round again with the pressure cap removed and if possible with the front of the car slightly elevated.
Please report back and let usknow if this sorts it, if not then thinking caps on.
If not then I think you may have lost some coolant and got an air lock as well, try bleeding the passenger side rail with the engine running, if fact start at the rad and work you way round again with the pressure cap removed and if possible with the front of the car slightly elevated.
Please report back and let usknow if this sorts it, if not then thinking caps on.
This evening I massaged some of the water hoses and I think I made the level in the expansion tank go down a little but not much.
I then bled the system and found no air.
Every pipe I squeeze caused a splut of water to run back into the expansion tank which can be seen and heard through the tank.
Unbolted the near side air box and made space to unbolt the tank and slide it enough to remove the return hose.
This being a new silicon hose I was surprised at just how loose the jubilee clip was. I can't believe it was this loose. This is not just in need of a nip up campers... Anyhow, removed it and started the engine to see if fluid came out. It did not.
If I understand the 3 way thermostat if it is open then the water is routed via the radiator. If closed it is routed back to the engine. So what ever way a broken thermostat might be stuck I should always see water being pumped back to the expansion tank, regardless of engine temperature – correct?
If the system is bled and so the impeller is not spinning air then does this point to something horrible?
I then bled the system and found no air.
Every pipe I squeeze caused a splut of water to run back into the expansion tank which can be seen and heard through the tank.
Unbolted the near side air box and made space to unbolt the tank and slide it enough to remove the return hose.
This being a new silicon hose I was surprised at just how loose the jubilee clip was. I can't believe it was this loose. This is not just in need of a nip up campers... Anyhow, removed it and started the engine to see if fluid came out. It did not.
If I understand the 3 way thermostat if it is open then the water is routed via the radiator. If closed it is routed back to the engine. So what ever way a broken thermostat might be stuck I should always see water being pumped back to the expansion tank, regardless of engine temperature – correct?
If the system is bled and so the impeller is not spinning air then does this point to something horrible?
The fans seem to be cutting in fine. The issue seems to be that the water is not being circulated through the radiatot so perhaps thermostat OR not being circulated at all in which case airlock, blockage or failed water pump.
As far as i can see if the thermostat is stuck shut it should send the water back to the engine so the water always flows?
Can anyone tell me if the return water from the engine should be seen coming into the expansion tank in the same way as when i squeeze a hose? Does this happen when the engine is cold? Would someone with a V8 take a look for me?
I am trying to work out the water flow but have not seen a clear diagram on the web so far. The two rails seem to be connected at the back of the engine into a Y connector which goes into the expansion tank hence my question. Is this correct?
Thanks
As far as i can see if the thermostat is stuck shut it should send the water back to the engine so the water always flows?
Can anyone tell me if the return water from the engine should be seen coming into the expansion tank in the same way as when i squeeze a hose? Does this happen when the engine is cold? Would someone with a V8 take a look for me?
I am trying to work out the water flow but have not seen a clear diagram on the web so far. The two rails seem to be connected at the back of the engine into a Y connector which goes into the expansion tank hence my question. Is this correct?
Thanks
wurgle said:
Yep will report back on g's post. Having troublecgetting to some of the hoses as i cant work out how to remove the f1 panel without disconnecting the top radiator hose.
New or old car (high or low f1 panel?)Low f1 panel you remove the flexy air hoses, then it's possible to wiggle the panel out, drivers side first
Low F1 panel 1998 vintage. I've removed the hoses and also the drivers side airbox but still can't fathom it. Current plan is to take it to Neil G's where i can get without overheating. That will give me a diagnosis and if it is the waterpump then thats past my capability. Also show me how to remove that f1 panel...
wurgle said:
Low F1 panel 1998 vintage. I've removed the hoses and also the drivers side airbox but still can't fathom it. Current plan is to take it to Neil G's where i can get without overheating. That will give me a diagnosis and if it is the waterpump then thats past my capability. Also show me how to remove that f1 panel...
Unless your oil pressure is very erratic, it is very unlikely to be the water pump(s).You just have to be firm but fair with the F1 Panel to manoeuvre it past the hose. I have also increased the cutout around the fan to make it slightly easier.
Spoke to Racetech today. Got some good advice which was to open a rail bleed valve when the engine was cold (so no pressure in the system) then start the car and rev to 2000---3000 RPM. If pump working I should see a spout of water from the nleed. Tried both sides and got about a 3cm...4cm water spout. Mopped up the mess and will order a thermostat as the pump seems to be working. Should be able to get it delivered Friday AM to my work so get Neil to fit Friday PM and give the car the once over.
Oil pressure is fine as is the PAS so my thought was that the pump was OK but given my luck so far... - the water works must have some very strange plumbing.
My understanding of the thermostat was also wrong I think in that it always has a bypass but if you look at this
http://www.racetechdirect.co.uk/e2713-tvr-car-part...
which is the race tech after market part its my guess its not a switch but that the bypass is always on and it makes a low impedance path to radiator when the thermostat switches.
Anyhow - I shall see if I can order one and post progress
Onwards and downwards
Wurgle
PS sorry about spelling - every word is shown as an spooling error for some reason...
Oil pressure is fine as is the PAS so my thought was that the pump was OK but given my luck so far... - the water works must have some very strange plumbing.
My understanding of the thermostat was also wrong I think in that it always has a bypass but if you look at this
http://www.racetechdirect.co.uk/e2713-tvr-car-part...
which is the race tech after market part its my guess its not a switch but that the bypass is always on and it makes a low impedance path to radiator when the thermostat switches.
Anyhow - I shall see if I can order one and post progress
Onwards and downwards
Wurgle
PS sorry about spelling - every word is shown as an spooling error for some reason...
The RT advice looks great, but the Aux Shaft failure mode is intermittent and probably heat related, as even though the Woodruff key may have failed, there is sometimes sufficient friction for the pumps to work, a bit, sometimes.
However, my understanding is that oil and water pumps usually fail in unison.
However, my understanding is that oil and water pumps usually fail in unison.
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