John C Roberts Posted April 4 Report Share Posted April 4 Hi Guys Came back from a run out this afternoon. 10 minutes later coolant on the drive A quick run of the engine with the rad cap off the coolant foamed up and flowed up out of the rad. Just done a compression test and leak down, Both excellent results. There is no coolant in the oil The coolant I am using is 4 Advanced Engine Coolant I would be grateful for any suggestions Regards JohnR Quote Link to post Share on other sites
Peter Cobbold Posted April 4 Report Share Posted April 4 Thermostat stuck closed ? What did temp gauge show? Not sure what your coolant is, do you know its boling point ? Quote Peter Quote Link to post Share on other sites
RobH Posted April 4 Report Share Posted April 4 (edited) Well according to the technical data that stuff doesn't boil until 180ºC so it shouldn't be that. https://4lifecoolant.co.uk/technical According to the hazard data sheet it's mainly a water/glycol mix ( up to 60% glycol ) with up to 5% other additives https://res.cloudinary.com/baywa-ag-p/raw/upload/A16879004.pdf Edited April 4 by RobH Quote Link to post Share on other sites
John C Roberts Posted April 4 Author Report Share Posted April 4 Hi Guys Did not look at the gauge . The 1st thing I thought about was crack in the cylinder head , it as only done 360 miles since rebuilding the engine The head just had hardened valve seats fitted and gas flowed by Peter Burgess, Thanks JohnR Quote Link to post Share on other sites
BlueTR3A-5EKT Posted April 4 Report Share Posted April 4 (edited) What colour is the coolant now? It changes colour if combustion gasses are present. Red to yellow, reverts back once combustion gasses are gone. Was ALL the previous coolant, radiator and block, purged from the engine? Evans Coolant Co sell a clean and purge liquid they say must be used before filling with their product. If you read their spec. they say do not mix with anything. Maybe it causes the foaming. https://static1.squarespace.com/static/5aa8e520b98a7807c92a15f1/t/5ab4e7d7575d1f48a5be11ae/1521805273092/FORLIFE+PDS.pdf Edited April 4 by BlueTR3A-5EKT Quote Link to post Share on other sites
Mike C Posted April 4 Report Share Posted April 4 If you rev the engine with the radiator cap off, radiator full of coolant, do you see bubbles appear? Quote Link to post Share on other sites
John C Roberts Posted April 4 Author Report Share Posted April 4 Hi Guys Yes I rev'd the engine ant it came foaming up out of the rad. But it is the original red colour. The engine as been rebored and rebuilt with newly refurbished cyl. head and a new rad. I used compressed air blowout the heater matrix. Thanks JohnR Quote Link to post Share on other sites
Nigel Triumph Posted April 4 Report Share Posted April 4 I've used 4Life coolant for more than 20 years and never had a problem with it, so I'm inclined to think the foaming problem is caused by something other than the coolant. The leak down test and lack of oil/coolant mixing suggests the head gasket is sealing okay. If it's not the coolant type, the thermostat or the head gasket, there are a few other possibilities to consider, albeit less likely: - A weak radiator pressure cap... Be nice if it's was that simple! - Excessive scaling of water passages in the engine, leading to localised hot spots that cause the coolant to boil. The 6 cylinder engine's water jacket can sludge up badly at the back of the block around cylinder no.6. - Water pump impeller detached from shaft, so no coolant circulation. - Cracked head casting, as you suggested. Could the head have cracked through to a water passage when the hardened valve seat inserts were fitted? Good luck. I fear the cylinder head will need to be removed to find the source of the trouble. Nigel Quote Link to post Share on other sites
Mike C Posted April 4 Report Share Posted April 4 Forget the coolant colour. I'd check the coolant foam for combustion gases, in Australia a test kit for these gases is around $50. Quote Link to post Share on other sites
RobH Posted April 4 Report Share Posted April 4 4 minutes ago, Mike C said: Forget the coolant colour. I'd check the coolant foam for combustion gases, Mike - if you read the spec that coolant already has the tell-tale colour change stuff in it, to show presence of combustion products. Quote Link to post Share on other sites
Mike C Posted April 4 Report Share Posted April 4 6 minutes ago, RobH said: Mike - if you read the spec that coolant already has the tell-tale colour change stuff in it, to show presence of combustion products. OK. Could be heat soak from the block to the coolant -the 10 min delay is a characteristic of this cause-this has happened to me occasionally on 40+C deg days in an old V8 Holden after a few hours running at high speed. These days if this is likely to happen I idle the engine for 5 mins or so after stopping to cool things down. Quote Link to post Share on other sites
John C Roberts Posted April 5 Author Report Share Posted April 5 Hi Nigel Interesting you suggested weak rad. cap I had not fully locked it down the last time I checked the level !! Going check the thermostat this morning . Here's hoping Thanks for all the replies Regards JohnR Quote Link to post Share on other sites
rcreweread Posted April 5 Report Share Posted April 5 I thought Pete Burgess specifically stated not to use waterless coolant with his engines/heads but I might have been dreaming it! Cheers Rich C-R ( Crewe-Read) Quote Link to post Share on other sites
Nigel Triumph Posted April 5 Report Share Posted April 5 16 minutes ago, rcreweread said: I thought Pete Burgess specifically stated not to use waterless coolant with his engines/heads but I might have been dreaming it! Cheers Rich C-R ( Crewe-Read) 4Life coolant is not waterless, basically it is water/glycol mix with extra additives to give long term corrosion protection. The waterless coolant is from Evans. Nigel Quote Link to post Share on other sites
DenisMc Posted April 5 Report Share Posted April 5 Hi John, I experienced something very similar with my TR5 recently. I took it out for a run and then left it idling for a while in my garage. On checking around the car I was greeted by a pool of blue coolant (it has a water and Bluecol antifreeze mix) by the nearside front wheel. The expansion bottle had overflowed. I checked the radiator cap and it was not in great condition so have replaced it with a good quality stainless steel cap from Tudor through BBclassics on eBay. I have since run the car up to normal temperature with no issues. So I would try that first. The TR6 may run at a higher pressure that the 5 so you need to get the correct cap. Good luck, Denis Quote Link to post Share on other sites
stuart Posted April 5 Report Share Posted April 5 3 hours ago, DenisMc said: Hi John, I experienced something very similar with my TR5 recently. I took it out for a run and then left it idling for a while in my garage. On checking around the car I was greeted by a pool of blue coolant (it has a water and Bluecol antifreeze mix) by the nearside front wheel. The expansion bottle had overflowed. I checked the radiator cap and it was not in great condition so have replaced it with a good quality stainless steel cap from Tudor through BBclassics on eBay. I have since run the car up to normal temperature with no issues. So I would try that first. The TR6 may run at a higher pressure that the 5 so you need to get the correct cap. Good luck, Denis I hope the cap you bought is a proper recovery cap with the two seals. Stuart. Quote Link to post Share on other sites
stuart Posted April 5 Report Share Posted April 5 17 hours ago, John C Roberts said: Hi Guys Came back from a run out this afternoon. 10 minutes later coolant on the drive A quick run of the engine with the rad cap off the coolant foamed up and flowed up out of the rad. Just done a compression test and leak down, Both excellent results. There is no coolant in the oil The coolant I am using is 4 Advanced Engine Coolant I would be grateful for any suggestions Regards JohnR Has the head been re-torqued since it was built? Stuart. Quote Link to post Share on other sites
DenisMc Posted April 5 Report Share Posted April 5 (edited) 58 minutes ago, stuart said: I hope the cap you bought is a proper recovery cap with the two seals. Stuart. Hi Stuart, Yes it has the two seals and correctly allowed coolant to be drawn back into the radiator as the system cooled down. In my case the problem might have been caused by heat soak, as suggested by MikeC... Denis Edited April 5 by DenisMc Quote Link to post Share on other sites
John C Roberts Posted April 5 Author Report Share Posted April 5 Hi Guys Panic over very simple solution, just make sure the rad cap is securely fastened. I think the low level of coolant caused what looked like foaming. Re-Torque the Head is the next job, Now done 400 miles running in and oil change Thanks for the Forum. Regards JohnR Quote Link to post Share on other sites
Motorsport Mickey Posted April 5 Report Share Posted April 5 "Re-Torque the Head is the next job" Don't forget to UNDO the nuts first by about 1 flat, (I do it in the torquing sequence) don't be surprised when it torques back up past where it was before. Mick Richards Quote Link to post Share on other sites
Peter Cobbold Posted April 6 Report Share Posted April 6 Is retorqeuing advised with Payen gaskets that have the heat-activated varnish coating ? loosening might break that seal. Quote Link to post Share on other sites
Andy Moltu Posted April 7 Report Share Posted April 7 Re torquing shouldn’t break the seal. Composite gaskets to compress with time and heat cycles. Most of this happens early on. On a newly rebuilt engine, My preference is to do the 20 min run if breaking a cam in. Then a few miles up the road. Off with the rockers and retorque. Do the nuts one at a time in the sequence in the workshop manual. As Mick says back of the nut a little so that if it’s stuck down you don’t have to break the static friction when tightening up. Do again after 500 to 1000 miles. Most of the movement is at the very first retorque. Quote Link to post Share on other sites
astontr6 Posted April 16 Report Share Posted April 16 On 4/4/2024 at 11:30 PM, Nigel Triumph said: I've used 4Life coolant for more than 20 years and never had a problem with it, so I'm inclined to think the foaming problem is caused by something other than the coolant. The leak down test and lack of oil/coolant mixing suggests the head gasket is sealing okay. If it's not the coolant type, the thermostat or the head gasket, there are a few other possibilities to consider, albeit less likely: - A weak radiator pressure cap... Be nice if it's was that simple! - Excessive scaling of water passages in the engine, leading to localised hot spots that cause the coolant to boil. The 6 cylinder engine's water jacket can sludge up badly at the back of the block around cylinder no.6. - Water pump impeller detached from shaft, so no coolant circulation. - Cracked head casting, as you suggested. Could the head have cracked through to a water passage when the hardened valve seat inserts were fitted? Good luck. I fear the cylinder head will need to be removed to find the source of the trouble. Nigel The company that did my head and fitted valve seat inserts insisted that after putting the inserts in that the head would be subject to a 24 hour pressure test lo look for leaks as they had a number of Triumph heads show porosity and leak after doing this type of work, But they had a cure for that where they would send the head to a local company to have it sealed called Vacublast. I have seen this treatment used on a Mini Cooper S block that was porous between 3 & 4 cyls and it cured that. Bruce. Quote Link to post Share on other sites
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