V6 Overheating
Discussion
Some advice please..... My essex has alway behaved itself in the temperature department up until the last run out before I put it away for the winter. On that last run it did odd things that lead me to believe that the thermostat had stuck. So, out it came and in went a new one. Now, this last Friday it actually stopped raining for an hour or two (and the wife was out and the kids were still at school) so off I went to "test a little petrol" as they say. Well the temp went up to the right hand end of the gauge and refused to come back down.
On investigation I found the system still full but although the top hose and the top of the radiator were hot the bottom hose and bottom of the rad were only warm. To me this suggests either a blocked bottom hose or radiator, blockage in the block somewhere or a failed water pump.
Before I drain the system (and soak the garage floor) does anyone have any other ideas?
On investigation I found the system still full but although the top hose and the top of the radiator were hot the bottom hose and bottom of the rad were only warm. To me this suggests either a blocked bottom hose or radiator, blockage in the block somewhere or a failed water pump.
Before I drain the system (and soak the garage floor) does anyone have any other ideas?
Has it Boiled on you?
If no then it could be a faulty guage or sender. Test with an in line temp guage.
Alternatively if you have an old rad and the car has stood then it is more likely that the rad has allowed the sludge / scale etc to settle over the lay up period.
Try to keep your feet dry.
Neil.
PS I will buy it for £2500
N.
Forgot to add. You haven't air locked it when you have changed the stat have you??
If no then it could be a faulty guage or sender. Test with an in line temp guage.
Alternatively if you have an old rad and the car has stood then it is more likely that the rad has allowed the sludge / scale etc to settle over the lay up period.
Try to keep your feet dry.
Neil.
PS I will buy it for £2500
N.
Forgot to add. You haven't air locked it when you have changed the stat have you??
Edited by heightswitch on Monday 15th January 13:29
Hi Neil, No didn't actually boil but damn close - and much hotter than usual. It's the difference in temps between top & bottom hoses that makes me think it's not just the guage - but I'm open to persuasion!
BTW, £2500 - you wouldn't want it!
BTW, £2500 - you wouldn't want it!
Edited by ATE399J on Monday 15th January 14:18
I have just run into similar problems with the temperature guage hitting the hard stop and boiling over with the top hose hot and the bottom hose cold (not warm).
This only happened when the car was sat idling - ie waterpump not running at max.
The diagnosis was a partly blocked radiator. The radiator was the old style brass one. It flowed with a hosepipe attached to it but sludge came out as well ....
I've bitten the bullet and I'm replacing the radiator with an alloy one - I get 50% weight saving + 20% more efficiency.
ProAlloy have the old radiator and are copying it as we speak ready for the end of the month ....
www.proalloy.co.uk
I did however decide to swap the waterpump/thermostat at the same time to be done with it.
I had a similar problem which turned out to be a combination of a faulty voltage regulator and the fact that the temp. guage was (incorrectly)connected to the unregulated side of the regulator itself. Been spot on 
since I replaced the reg. and changed the wiring .. however, my fuel gauge now reads low, whereas previously it read high 
... but that's probably to do with the sender and/or difficulty to fill the tank completely.
Here's another thread on a similar subject -> www.pistonheads.co.uk/gassing/topic.asp?t=106023&f=34&h=0&hw=overheating
since I replaced the reg. and changed the wiring .. however, my fuel gauge now reads low, whereas previously it read high ... but that's probably to do with the sender and/or difficulty to fill the tank completely.
Here's another thread on a similar subject -> www.pistonheads.co.uk/gassing/topic.asp?t=106023&f=34&h=0&hw=overheating
Hey Duncan, you mean you don't carry a calibration device (aka bamboo stick?), just kidding, although I heartly recommend not dropping a Yakult pot of Red-X into the fuel tank, slippery little bu@@ers that need long pointy fingers to get out. Moral: (a) use the pot it comes in, or (b)always travel with a Lemur.
Ahem: back to the dodgy rad. Don't kid yourself that after umpteen months inactivity the rad won't have sludged up, choose a reasonably nice day and drain everything and start over, almost bound to improve things.
Ahem: back to the dodgy rad. Don't kid yourself that after umpteen months inactivity the rad won't have sludged up, choose a reasonably nice day and drain everything and start over, almost bound to improve things.
Hi Peter, you must be psychic 
...on the way back from today's TVRCC meet, heard a strange squeak from the engine bay .. turned out to be the pulley-wheel on the water pump nearly sheared off .... fan belt had jumped off.. a right state. Managed to get the belt off completely and gingerly drove the last mile home (freewheeling downhill)! Luckily, a cool day. So, system now drained and pump removed to be replaced .. so all in all, as you predicted !
Wonder why it failed ? It's less than 6 months old .... methinks a 'chat' with my supplier
...on the way back from today's TVRCC meet, heard a strange squeak from the engine bay .. turned out to be the pulley-wheel on the water pump nearly sheared off .... fan belt had jumped off.. a right state. Managed to get the belt off completely and gingerly drove the last mile home (freewheeling downhill)! Luckily, a cool day. So, system now drained and pump removed to be replaced .. so all in all, as you predicted ! Wonder why it failed ?
It's less than 6 months old .... methinks a 'chat' with my supplier Tks .. I'll be sure to check that.
Actually, the spindle of the old pump was okay .. it was the pully-wheel which had ripped away from it's mounting, which was half a dozen spot-welds onto the spindle plate.
Interestingly, on the replacement pump I've just fitted, the pulley wheel is fixed to it's spindle plate by three good sized bolts .. no spot welding ... makes you wonder !
Best get a new fan belt as well ...if I remember correctly, 0.9mm x 1300mm ? Could someone confirm
Actually, the spindle of the old pump was okay .. it was the pully-wheel which had ripped away from it's mounting, which was half a dozen spot-welds onto the spindle plate.
Interestingly, on the replacement pump I've just fitted, the pulley wheel is fixed to it's spindle plate by three good sized bolts .. no spot welding ... makes you wonder !
Best get a new fan belt as well ...if I remember correctly, 0.9mm x 1300mm ? Could someone confirm
Rob, I'm shouting!
So far I've had the water pump off and stripped it down - nothing obvoiusly wrong and the fact I could get it off the car suggests that it's a replacement (or it'd be siezed in place). I've run water through the block - from thermostat housing - and seen it coming out of the bottom hose (pump in place). Had the rad off and flushed it through - nothing much in it that would have blocked it. I've run water through the header tank and rad and out of the bottom of the rad. All this to no avail.
So, I can only guess that the water pump is the problem. If the cast ones are the best where can I get one. Demon Tweeks will sell me one (£50 in my hands) but I guess that's not the cast variety.
Phil.
So far I've had the water pump off and stripped it down - nothing obvoiusly wrong and the fact I could get it off the car suggests that it's a replacement (or it'd be siezed in place). I've run water through the block - from thermostat housing - and seen it coming out of the bottom hose (pump in place). Had the rad off and flushed it through - nothing much in it that would have blocked it. I've run water through the header tank and rad and out of the bottom of the rad. All this to no avail.
So, I can only guess that the water pump is the problem. If the cast ones are the best where can I get one. Demon Tweeks will sell me one (£50 in my hands) but I guess that's not the cast variety.
Phil.
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