TReslaV8 Posted October 3, 2017 Report Share Posted October 3, 2017 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! Quote Link to post Share on other sites
MadMarx Posted October 3, 2017 Report Share Posted October 3, 2017 Hi, a darkish coolant color might inidcate a leaking head gasket? Cheers Chris Quote Link to post Share on other sites
Chris59 Posted October 4, 2017 Report Share Posted October 4, 2017 Absolutly right Chris, suspect some compression from one (or more) cylinder in the cooling system. Quote Link to post Share on other sites
TReslaV8 Posted October 4, 2017 Author Report Share Posted October 4, 2017 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 Quote Link to post Share on other sites
Jeff Eatough Posted December 8, 2017 Report Share Posted December 8, 2017 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 Quote Link to post Share on other sites
acaie Posted December 11, 2017 Report Share Posted December 11, 2017 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 . Quote Link to post Share on other sites
Alec Pringle Posted December 11, 2017 Report Share Posted December 11, 2017 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 Quote Link to post Share on other sites
TReslaV8 Posted January 8, 2018 Author Report Share Posted January 8, 2018 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! Quote Link to post Share on other sites
acaie Posted December 29, 2018 Report Share Posted December 29, 2018 (edited) 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 . 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 December 29, 2018 by acaie posted in wrong thread Quote Link to post Share on other sites
UlsterTR7 Posted January 6, 2019 Report Share Posted January 6, 2019 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. Quote Link to post Share on other sites
Smiffy_69 Posted April 3, 2021 Report Share Posted April 3, 2021 Hi, I've just fitted a 3.9L in to my TR8 convertible taken out of a Discovery which has been skimmed and fitted with new head gaskets. I've fitted it with a four barrel holley carb, so my return has gone. I've made a joiner up top hose for the return to the header. The problem I'm having is the water doesn't seem to be circulating, which causes the water to get hot. It then starts pumping out of the header tank, or with the cap on pressurises the hose, which goes rock hard so the cap gives way. I don't have any pictures or diagram of how the water system should be so I'm just guessing! The original -P6 engine (with SDI heads) was putting exhaust gasses into the header tank. I had the heads skimmed but there was no difference! I thought it was the liner seals. Hence me going for 3.9 engine. I'm at my whit's end so any advise or help would be much appreciated. Thanks, Paul Quote Link to post Share on other sites
acaie Posted April 4, 2021 Report Share Posted April 4, 2021 Looking at the top hose configuration I would think about it air locking. The vent you have connecting to the expansion tank looks too low down to get the air out. If you can get it at or much nearer to the highest point in the top hose it may help. Quote Link to post Share on other sites
Melcoagain Posted April 6, 2021 Report Share Posted April 6, 2021 Well the obvious answer to your question is that the radiator is blocked. A messy test for that would be to disconnect the top and bottom hose from the rad. Then use the garden hose in the top hose position and check the water flows. Might be worth doing the reverse while your at it then again from the top. That should give it a bit of a clear out anyway. Quote Link to post Share on other sites
BusheyTrader Posted May 26, 2021 Report Share Posted May 26, 2021 What hoses do you have connected at the rear of the inlet manifold? The heater matrix is permanently connected to the coolant circuit. Quote Link to post Share on other sites
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.