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TReslaV8

TR7 V8 Overheating

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Hi there, as newbie TR7 V8 owner, I have acquired a recent conversion with (I think) an SD1 V8 which on a recent run round the M25 and M3 at a steady 50-70mph (yes even on the M25!) the temp gauge showed N but upon stopping at Fleet services some steam wisped out. Opened the bonnet, and much steam, quite a bit from around the exhaust manifold, and loosening the overflow tank cap, a lot of pressurised hot water spurted out.

 

So the car has new rad, twin fans (which are working) , the heater still pumping out hot air into the car, belts tight, but the coolant (which was replaced only a few weeks back) looks dark (& dare I say it, oily) but no sign of creamy deposits anywhere.

 

I did notice a couple of strips of (what looked like) red elastic band being ejected with the coolant suggesting a gasket has gone somewhere in the system.

 

Ideas welcome, but I am thinking I need a new thermostat, and/or water pump, not least as some evidence of wetness on the low cross member under the front of the engine.

 

Thanks!

 

 

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Hi,

a darkish coolant color might inidcate a leaking head gasket?

 

Cheers

Chris

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Absolutly right Chris, suspect some compression from one (or more) cylinder in the cooling system.

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Many thanks both, I feared that the head gasket may be the issue but hoped for a simpler answer . I will investigate further at the weekend when I can get under the bonnet.

 

Thanks for your advice.

 

David aka TReslaV8

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You mention coolant replaced few weeks back. I'm no expert but recall many comments that the Rover V8 is a sod to get all the air out of the system. May be worth a check on V8 related forums on correct filling etc procedure before tearing everything apart.

Jeff

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Air locks in the top hose can often be a problem. To specifically address air lock problems,

 

1) you need to drill a 3mm hole or two in the thermostat to allow the air into the top hose even if the thermostat is closed.

 

2) it makes it a lot easier if you fit a forging with a vent plug in the top hose to let the air out as you fill up, and add the last little bit of water direct into the top hose to get it really full. You can get the forging from revotec and it takes a standard 3/8 bsp plug.

 

If you have overheating probems, also make sure the radiator cap seals OK since this will aggravate them.

 

There's quite a lot on this forum and on others abut Rover V8 overheating. I think the TR7 installation can be quite prone to it. In my Grinnall the top of the top hose is actually above the top of the header tank, making it more difficult to fill.

 

Good luck.

Al

 

.

 

 

 

post-10663-0-46237500-1513008856_thumb.jpg

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Detach the header tank, and hold it up in the air whilst filling . . . . that generally shifts the usual airlock resulting from the thermostat and/or top hose being above the header tank as mounted.

 

If the engine has got that hot, as in steaming under the bonnet, then you've almost certainly cooked it by now - the water pump and thermostat may be OK, the gaskets around them probably not.

 

If the head gaskets haven't blown already then they soon will, so you might as well get on and renew them anyway . . . . . . they never last long once a V8 has overheated.

 

Cheers

 

Alec

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Thanks for all the help and advice. Issued sorted and I feel something of a numbskull. Yes then engine was getting hot but what I took to be steam/boiling coolant was actually oil burning off - the car had a big oil leak which has now been sorted and problems resolved...well this one at least!

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On 12/11/2017 at 4:15 PM, acaie said:

Air locks in the top hose can often be a problem. To specifically address air lock problems,

 

1) you need to drill a 3mm hole or two in the thermostat to allow the air into the top hose even if the thermostat is closed.

 

2) it makes it a lot easier if you fit a forging with a vent plug in the top hose to let the air out as you fill up, and add the last little bit of water direct into the top hose to get it really full. You can get the forging from revotec and it takes a standard 3/8 bsp plug.

 

If you have overheating probems, also make sure the radiator cap seals OK since this will aggravate them.

 

There's quite a lot on this forum and on others abut Rover V8 overheating. I think the TR7 installation can be quite prone to it. In my Grinnall the top of the top hose is actually above the top of the header tank, making it more difficult to fill.

 

Good luck.

Al

 

 

.

 

 

 

post-10663-0-46237500-1513008856_thumb.jpg

There are lots of threads on TR7V8 overheating on TRR  and on TriumphTR7.com. My contribution to a relatively recent one is above. One other thing I discovered relatively recently was that my heater was leaking, so I bypassed the heater with ordinary 15mm piping and that made a substantial reduction in the running temperature. 

Best wishes

Al

 

Edited by acaie
posted in wrong thread

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On 1/8/2018 at 3:26 PM, TReslaV8 said:

Thanks for all the help and advice. Issued sorted and I feel something of a numbskull. Yes then engine was getting hot but what I took to be steam/boiling coolant was actually oil burning off - the car had a big oil leak which has now been sorted and problems resolved...well this one at least!

Well done, I'm sure you're relieved that it's not a head gasket.

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