Jonathan Smith Posted August 19, 2019 Report Share Posted August 19, 2019 I have an early TR2 longdoor TS349 with the early thermostat housing and no heater. The car was restored 25 years ago and has covered little mileage since the restoration.The car has been recommissioned over last few month having now covered in excess of 900 miles. The problem I am having is that once engines is run at speed in excess of 40mph for any extended time the temperature gradually increases and once engine speed is reduced below 40mph engine temperature drops down. There are no apparent water leaks or trapped air. I have a new boxed moss uprated water pump purchased some things me ago for my TR4 which I am considering fitting with new replacement bellows thermostat. It would appear that the problem is flow related . The engine and radiator have been flushed and all houses replaced. Any thoughts re possible cause and remedy? Quote Link to post Share on other sites
foster461 Posted August 19, 2019 Report Share Posted August 19, 2019 Hi Jonathan and welcome. Just because the rad and engine have been flushed doesnt mean they are clear of restricted passageways. The crud that builds up sets like concrete and a normal flush would not clear it. The 4 pot engine is very prone to the last cylinder liner getting a lot of sediment around it and an infra red thermometer might help you determine if there is a particular hot spot. Normally things cool down as you speed up so something definately not doing its job. Stan Quote Link to post Share on other sites
RobH Posted August 19, 2019 Report Share Posted August 19, 2019 Are you sure the thermostat is opening fully? Quote Link to post Share on other sites
Jonathan Smith Posted August 19, 2019 Author Report Share Posted August 19, 2019 28 minutes ago, foster461 said: Hi Jonathan and welcome. Just because the rad and engine have been flushed doesnt mean they are clear of restricted passageways. The crud that builds up sets like concrete and a normal flush would not clear it. The 4 pot engine is very prone to the last cylinder liner getting a lot of sediment around it and an infra red thermometer might help you determine if there is a particular hot spot. Normally things cool down as you speed up so something definately not doing its job. Stan Just opened up the brass tap on the block next to number 4 cylinder and no water flow. Cleared water the way with a welding rod and water is now flowing fast and clear. Going to try fast run tomorrow and hopefully may be sorted. Feels like too easy too a fix but fingers crossed Quote Link to post Share on other sites
Jonathan Smith Posted August 19, 2019 Author Report Share Posted August 19, 2019 14 minutes ago, RobH said: Are you sure the thermostat is opening fully? Hoping that clearing number 4 cylinder water way my have help but if tomorrow’s run doesn’t show any improvement next port of call will be checking thermostat. Will keep you posted. Thanks for help Quote Link to post Share on other sites
foster461 Posted August 19, 2019 Report Share Posted August 19, 2019 3 minutes ago, Jonathan Smith said: Just opened up the brass tap on the block next to number 4 cylinder and no water flow. Cleared water the way with a welding rod and water is now flowing fast and clear. Going to try fast run tomorrow and hopefully may be sorted. Feels like too easy too a fix but fingers crossed Well you get bonus points for getting the tap to open without the handle shearing off and double extra points for getting anything to come out of it. All positive signs for the block. Stan Quote Link to post Share on other sites
Fireman049 Posted August 19, 2019 Report Share Posted August 19, 2019 (edited) . Edited April 15, 2020 by Fireman049 Quote Link to post Share on other sites
Drewmotty Posted August 19, 2019 Report Share Posted August 19, 2019 40 minutes ago, Jonathan Smith said: Just opened up the brass tap on the block next to number 4 cylinder and no water flow. Cleared water the way with a welding rod and water is now flowing fast and clear. Going to try fast run tomorrow and hopefully may be sorted. Feels like too easy too a fix but fingers crossed Unfortunately I think that you may have only cleared the tap. The waterway can only be cleared by stripping the engine down. Quote Link to post Share on other sites
Jonathan Smith Posted August 19, 2019 Author Report Share Posted August 19, 2019 7 minutes ago, Drewmotty said: Unfortunately I think that you may have only cleared the tap. The waterway can only be cleared by stripping the engine down. Living in hope at the moment 7 minutes ago, Drewmotty said: Unfortunately I think that you may have only cleared the tap. The waterway can only be cleared by stripping the engine down. Quote Link to post Share on other sites
Z320 Posted August 20, 2019 Report Share Posted August 20, 2019 (edited) Here are some thoughts: if the coolant gets hot (energy flow from the cylinder liners in the coolant) - can this be a problem of crud in the engine? What temperature is the thermostat? Did you test the car driving without thermostat? Does the (your) TR2 have a radiator card board? What fan is on the engine? Ciao, Marco Edited August 20, 2019 by Z320 Quote Link to post Share on other sites
Lebro Posted August 20, 2019 Report Share Posted August 20, 2019 If thermostat seems ok then I would suspect partially blocked radiator. Bob. Quote Link to post Share on other sites
Pogo Posted August 20, 2019 Report Share Posted August 20, 2019 1 hour ago, Z320 said: Did you test the car driving without thermostat? Hi Jonathan I'd try that. It's easy to do and check without too much upheaval. Lovely car by the way. I didn't get chance to chat to you about it on Saturday. Roger Quote Link to post Share on other sites
MilesA Posted August 20, 2019 Report Share Posted August 20, 2019 (edited) Hi Jonathan A comprehensive account of potential causes of and possible solutions to overheating in the 4 cylinder engine can be found in this locked topic at the top of the General section. https://www.tr-register.co.uk/forums/index.php?/topic/58689-4-cylinder-hot-engine-causesanswers/ Miles Edited August 20, 2019 by MilesA Quote Link to post Share on other sites
Jonathan Smith Posted August 20, 2019 Author Report Share Posted August 20, 2019 17 hours ago, Drewmotty said: Unfortunately I think that you may have only cleared the tap. The waterway can only be cleared by stripping the engine down. Living in hope at the moment 17 hours ago, Drewmotty said: Unfortunately I think that you may have only cleared the tap. The waterway can only be cleared by stripping the engine down. Overheating update. Firstly thank you everyone who has replied to the post. Test run completed. Before the run I checked the engine drain tap again and as last night water flowed clean and fast with no sign of rust or water staining. Checked spark plugs and engine has been running a little rich so weakened mixture slightly. Then ran engine with rad cap removed and couldn't get temperature gauge past quarter mark circa 135f. No noticeable drop in water level but not surprising at thermostat will not have opened. Ran car up to motorway in traffic circa two miles at max 30mph no increase in temperature followed by 10 miles of motorway at between 55 and 60mph.Once car was running at speed temperature gauge relatively quickly increasing to fraction over the half way mark 185f. Once off the motorway with speed reduced to around 45mph temperature reduced to fraction under 185f. On returning home checked the radiator water temperature with an electric temperature gauge and had very similar reading to cars gauge. Checked plugs and now only marginally rich. Appears to be some improvement but not yet convinced problem is solved. Many thanks for all the contributions all of which are greatly appreciated as the target is to make sure the car is sort ready for the Bo’ness revival next weekend to celebrate 65 th anniversary of the car racing at Bo’ness on 4th September 1954. Its a long run over 650miles in total there and back and don’t fancy entire journey at 40mph. Next port of call I suspect will be thermostat checks and Roger suggests and than possible water pump and progressively working through the closed post off Miles one stage at a time. Any other suggestions or possible quick fixes will be very welcome Jonathan Quote Link to post Share on other sites
Hamish Posted August 20, 2019 Report Share Posted August 20, 2019 Jonathan those temps don’t look bad to me. Just over 185f 85-90c with 4lb pressure cap it’s well away from boiling. Do you lose water on a run? Mine runs up to the the next temp gauge mark that is about 207f 97c my elec fan controls this back down to 185f happens a lot waiting for sprint and hill climb runs. I also run an expansion tank so never lose water. I know you have a very original car. So just make sure your temps are not too hot ie boiling do you have fresh antifreeze this helps raise boiling point it may just run hotter on the gauge. Rich is better and cooler than lean. Quote Link to post Share on other sites
Jonathan Smith Posted August 20, 2019 Author Report Share Posted August 20, 2019 15 minutes ago, Hamish said: Jonathan those temps don’t look bad to me. Just over 185f 85-90c with 4lb pressure cap it’s well away from boiling. Do you lose water on a run? Mine runs up to the the next temp gauge mark that is about 207f 97c my elec fan controls this back down to 185f happens a lot waiting for sprint and hill climb runs. I also run an expansion tank so never lose water. I know you have a very original car. So just make sure your temps are not too hot ie boiling do you have fresh antifreeze this helps raise boiling point it may just run hotter on the gauge. Rich is better and cooler than lean. Hi Hamish thanks for the info. I’m on 4psi cap and water didn’t boil today although temperature did get higher on way back from Stratford on Monday and was just starting to boil. No electric fan on the 2 as it’s running with factory set up and ideally I’d like to keep it that way if possible and have been thinking about acontinental fan upgrade as an option Not losing any water although if I overfill the radiator neck does dump water due to expansion so tending to fill approx 1inch below rad cap and this appears to work ok Going to check thermostat next and refresh antifree to see if this help a little more Because the car and engine were rebuilt 25 years ago ago and only covered 300 miles before being put into storage as part of the recommissioning work we have been keeping engine revs down around 2000 to 2250 max for the last 1000 miles miles and have only just started to slowly increase engine speed which has resulted in temperature increase. Feel a little better knowing yours get just over 185f although I don't expect I’ll be running at the speed you do. Jonathan PS if you are going to the gold cup at the weekend arrangements for picking up tickets are on Facebook. Quote Link to post Share on other sites
BlueTR3A-5EKT Posted August 20, 2019 Report Share Posted August 20, 2019 (edited) Did the head get re torqued? That may be an issue as you only have done 300 miles on this engine. it will run hotter if it is a new engine. Peter W Edited August 20, 2019 by BlueTR3A-5EKT Quote Link to post Share on other sites
foster461 Posted August 21, 2019 Report Share Posted August 21, 2019 4 hours ago, Hamish said: Jonathan those temps don’t look bad to me. Just over 185f 85-90c with 4lb pressure cap it’s well away from boiling. Do you lose water on a run? Mine runs up to the the next temp gauge mark that is about 207f 97c my elec fan controls this back down to 185f happens a lot waiting for sprint and hill climb runs. I also run an expansion tank so never lose water. I know you have a very original car. So just make sure your temps are not too hot ie boiling do you have fresh antifreeze this helps raise boiling point it may just run hotter on the gauge. Rich is better and cooler than lean. My TR3a has under 1000 miles since the engine rebuild and refurbed radiator. It has the bellows thermostat and a 4lb rad cap. Its running temp is 185f, the middle of the dial. If the car stays moving it will stay at that temp all day but if I get stuck in traffic on a hot day it will creep up to the next tick on the gauge just like Hamish. Once moving again it will slowly return to 185 and at no time do I feel like the engine is in distress. I on the other hand get very hot when it is 100 degrees out and very high humidity like most of July. Stan Quote Link to post Share on other sites
Jonathan Smith Posted August 21, 2019 Author Report Share Posted August 21, 2019 (edited) 21 hours ago, BlueTR3A-5EKT said: Did the head get re torqued? That may be an issue as you only have done 300 miles on this engine. it will run hotter if it is a new engine. Peter W Thanks for reminding me about the cylinder hard re torque. This should have been high on the recommissioning list but some how didn’t think about it. If I hadn’t posted on the forum could have ended up with a costly problem. Re torqued the head this evening and re set tappets and new bellows thermostat due at the weekend and with some luck all will be good. Cant thank you enough for the reminder about the cylinder head and just shows it’s always worth sharing a problem even if you think you know the answer as could be something basic you have forgotten Many thanks Jonathan Edited August 21, 2019 by Jonathan Smith Quote Link to post Share on other sites
BlueTR3A-5EKT Posted August 21, 2019 Report Share Posted August 21, 2019 Just took the bellows stat out of my car and replaced it with a Tridon item which is a modern wax type item without blanking sleeve. The bypass has a restriction down to 8 mm in it.. Reason for doing this change was erratic temp. Under 185 for entire 100 miles to IWE them a needles width over 185= all the way home later in the day Temp is now solidly on 185 including motorway and A roads. Cheers Peter W Quote Link to post Share on other sites
Z320 Posted August 22, 2019 Report Share Posted August 22, 2019 Hi Peter, you know about my "long time bellows with sleeve - experiment". In my opinion to get rid of the sleeved bellows and use a wax thermostat with 8 - 9 mm bypass will finally be a very goog idea. Ciao, Marco Quote Link to post Share on other sites
Hamish Posted August 22, 2019 Report Share Posted August 22, 2019 22 hours ago, BlueTR3A-5EKT said: Just took the bellows stat out of my car and replaced it with a Tridon item which is a modern wax type item without blanking sleeve. The bypass has a restriction down to 8 mm in it.. Reason for doing this change was erratic temp. Under 185 for entire 100 miles to IWE them a needles width over 185= all the way home later in the day Temp is now solidly on 185 including motorway and A roads. Cheers Peter W Can I ask another numpty question is this the bypass hose that benefits from the 8mm restriction? does one install a stainless / Ali washer type thing ? i presume is encourages more water through the rad ? thanks H Quote Link to post Share on other sites
Drewmotty Posted August 22, 2019 Report Share Posted August 22, 2019 That’s it Hamish. People use all sorts to restrict it. I favour a nylon plug about 25mm long with the o/d machined to just slide into the hose. If you ask what size the hole should be you get answers varying from 8mm down. I know that some people completely block it. I have a plug with a 6mm orifice in one car and the other runs a plug with a 3mm orifice just to allow any trapped air out. Both cool slightly better with the plug but I haven’t been able to detect any difference when changing from a 6mm to a 3mm orifice. Quote Link to post Share on other sites
Z320 Posted August 23, 2019 Report Share Posted August 23, 2019 (edited) Im my opinion the Triumph engineers did everything correct with the younger TRs. They reduced the bypass to about 8.5 mm on the TR4A water pump housing and down to 8 mm on the 6 cylinder water pump housing. With the wax thermostat opened it comes very fast to the point (on the TR4A) no water flows the bypass. I would not use less than 8 mm to have as much water flow as possible while the engine heats up. Ciao, Marco Edit: By the way, with my work on the cooling system one time I found the 8.5 mm bore particular blocked by a solid piece of rusty cast iron. No Problem with the 8 mm bore, but a 3 mm bore would have been blocked. Edited August 23, 2019 by Z320 Quote Link to post Share on other sites
TomMull Posted August 23, 2019 Report Share Posted August 23, 2019 On 8/20/2019 at 2:24 AM, Lebro said: If thermostat seems ok then I would suspect partially blocked radiator. Bob. I agree with Bob. I think it is unlikely that the block would be badly corroded after 25 years IF it was cleaned when restored and there was antifreeze in it. The radiator would be a far more likely suspect in my opinion and if that's the case even an in car flush might give you a few more degrees of cooling before your trip. Tom Quote Link to post Share on other sites
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