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MG TD TF 1500 - Overheating TD
| Can anyone recommend a company in the South East of England (Surrey/Hampshire) for recoreing a radiator. I have tried several thing now to cure an overheating problem in my 1951 TD without success, during an easy run yesterday of about 30 miles the car once again overheated, but this time in a big way, the engine sounded terrible but I managed to limp home, have not had the courage to restart it as yet... |
| John Craggs |
| John, sorry to hear of your problem. Are you sure it's the radiator - you will find loads of info in this site's archives on the possible causes and cures, the most common seems to be the slats in the grille being fitted the wrong way round ! If you're sure it's the radiator, then your local branch of Serck Marston should be able to recore, they have a classic car division. Good luck. David |
| avid Burgess |
| John, I'm curious what things you've tried so far to cure your overheating. Could you elaborate? I wish you good luck and I hope your engine is not to severely stressed from the event. dave |
| Dave Braun |
| Amazing the gunk that will come out if you do a good clean and flush... also look into/through the rad and make sure you haven't picked up a few years worth of little bugs... They can clog pretty well! |
| gblawson |
| Thanks for the quick responses, things tried or checked so far are timing and mixture, I've replaced the thermostat and blanked off the bypass (I tried it without a thermostat in the housing as well), flushed the rad both ways and with a descaler, checked the fan blades or on the right way, bent the grill slats to more of an angle to allow more air through etc. It was running with a 25% antifreeze mix with water, but it currently has ForLife in it as supplied by the MGOC which is supposed to help with heat dissipation and has a much higher boiling point. Any ideas on what damage I should look for when I eventually start it up again... |
| John Craggs |
| John, How is your water pump? That, and having an obstruction in the block comes to mind. I run with a small hole in the plug I put in the bypass, running without a thermostat didn't work for me, I think it allowed too much water to flow, with not enough dwell time in the radiator to cool it. Here in the US we also have a company called Jet-Hot which is a ceramic coating on the inside and outside of the manifold. It is supposed to reduce underhood temperatures significantly, I haven't tried my coated manifold yet, as I'm still in the rebuild stage. But I bought into that process more for the effect on fuel temperature than block temperature. Keep us posted please! dave |
| Dave Braun |
| JohnJohn You don’t say if this an ongoing problem with your engine. Or is it something that just developed. You might want to check your oil and see if it has water in it. Or check your coolant and see if it has oil. If so you might have a blown head gasket. (BTDT) I run my car without a thermostat and can see the water/coolant move through the radiator when is cold. That way I know my water pump is working. If you have pulled your thermostat you might want to check that you reinstalled it correctly. I once installed one backwards in a 54 ford truck and needless to say it over heated. Keep us posted as to your progress. John |
| John C. Hambleton III |
| John Please deduct one John from my previous post. I cut and pasted it from my Words/ Spell check, so the spelling police wouldn’t get me and made a FUPAW. John |
| John C. Hambleton III |
| John, Go to www.mg-tabc.org/. Click on the "Technology" tab on the left hand side. Scroll down to "The Hidden Water Passage" and click on it. I once had a TC that overheated after a complete rebuild of the engine and radiator in which the block and radiator were absolutely pristine inside. After much agravation during which we tried EVERYTHING, I finally discovered this "secret". Pulled the rear freeze plug and low and behold there was a piece of solder (from the radiator rework?)blocking the little hole. Removed it, replaced the freeze plug and... Bingo, no more overheating. I can't imagine why those little holes have that effect, but they do. Reed Yates Ft. Worth, Tx |
| Reed Yates |
| John above may be on to it. If oil and water clean, check compression. You can also use an emissions tester in the radiator fill neck while running to check for CO or exhaust gases escaping into the coolant. If your motor rattles/knocks/is down on power after overheating that is not good at all. My radiator core developed multiple leaks and was recored a couple years ago, now runs much cooler. George |
| George Butz |
| Thanks for the advice all, the overheating has been an ongoing problem but has been getting worse. I've checked the oil and there does not appear to be any water in it, the coolant is supposed to change colour if it has any exhaust gases in it, but it has not. I'm building up the courage to restart it, which I will probably do on Sunday when the wife will be out and will not be able to hear me if it sounds bad.... |
| John Craggs |
| Reed, Thanks for the tip, I'm rebuilding my engine right as we speak, and wasn't aware of this passage. dave |
| Dave Braun |
| I think you'll be all right on start up. When they overheat the valves get so hot that you get pre-ignition which will give you lots of expensive sounding rattles. Then, you get the engine running on after you switch off, again accompanied by loud detonation rattles. Usually the head gasket goes at this stage so let's hope you've been lucky. If the oil overheated and broke down, you could have some bearing damage - but I think this would be extreme- a check of oil pressure, hot but not overhot ! together with listening for rattle will tell you. Here's hoping you'll be fine. |
| David Burgess |
| Well it started Ok and there appears to be no odd noises, the oil pressure at idle when hot is about 45. The oil and coolant seem to be OK. I now need to try to get to the bottom of the overheating before I take it out again. I'll get some new core plugs and then remove the old ones to check for the small hole in the water jacket behind them, there seems to be conflicting views on this going through the archives but it seems to do no harm to have it. There seems to be some noise coming from the water pump whem the engine is reved, not much but probibly worth investigating - is it possile to remove it without taking the rad off first? |
| John Craggs |
| John, If this has been an ongoing problem you might want to take the time to check and make sure your head gasket has been installed the correctly. You can install it so that it blocks the main rear water passage from the block to the head. This still allows water to perculate up to the head through the smaller holes but you have very little flow. The engine will run fine but will start to overheat quicker than one with a head gasket installed correctly. Don't ask... Gene |
| Gene Gillam |
| John, You can remove the water pump with the radiator in place. Remove the four bolts to the fan, and remove the fan (note the position of the blades, they have to go back in the right order) and the spacer. Take off the fan belt and the hose to the branch pipe. Unbolt the water pump. The water pump lower fasteners also hold the engine stabilizing link. good luck, dave |
| Dave Braun |
| John; You stated the the coolant would change color if the head gasket starts to leak. I, myself have never seen that color change .I believe that the color change is in the blue liquid used to check for carbon monoxide, This liquid is in a syringe that you put in the top of the radiator when the coolant is hot. You draw air only through the syringe and if carbon monoxide is present the blue fluid turns to yellow like urine. I have used it many times and have found it very accurate. The first sign of gasket failure is exhaust gasses leaking into the coolant. This happens long before you have a full fledged coolant leak into the innards. Sandy Sanders |
| conrad sanders |
| John, Let go back to some simple tests before you tear your engine down. Rub your fingers along the radiator fins, both sides top and bottom, they should be firm, if the are brittle, powdered, rotted, etc. re-core the radiator. If they are firm, open the radiator cap while the engine is running, look for bubbles in the coolant. If you have bubbles, chances are you have a leaking head gasket ( or crack head or block) No bubbles, wait for the engine to warm up and see if you have a flow of coolant. If you have a flow of coolant, shut the engine off, this step should not be overlooked, and then put your hand on the radiator core and feel for cool spots. Side to side it should be the same temperture. If you do have cool spots, you have radiator blockage. |
| Ron Boisvert |
| Gene, I won't ask, but will say "been there, done that".... |
| Willem van der Veer |
| Thanks for the suggestions.. The radiator looks fine on the outside, all the fins are secure and you can see through (with a light on the inside) over the whole of the area. once warmed up the temp. feels pretty even over the whole radiator. There does not appear to be any bubbles in the coolant and there seems to be a flow of coolant with the engine hot and running, it does not seem to be much but there is some. The coolant in there is "Forlife" supplied by the MG Owners Club, in its normal state it is red but is supposed to trun yellow if and gasses from the engine get into it, it is still red. I've rechecked the timing, it is set to TDC static and is showing about 5 degrees advance with a timing light and the engine running at about 900 rpm. I think that I will get some new core plugs and check for the "hidden holes" in the water jacket. |
| John Craggs |
| John, It will be interesting to see what you find out. I finished restoring my TD last year and had the same overheating problem. I Blocked the by pass hole, opened up the slat in the radiator grill and installed a plastic MGB fan which has more blades and pulls more air. I also added "water Wetter" to my radiator coolant that helped to keep temp. down. The overheating went away and the the car was running at about 75 degree C or below. One day, after a fairly long run, the car died and did not want to start. After checking everything I found out that the points plate and the screws securing the points have rattled loose and the point gap was zero. After fixing this problem, the car runs fine but the overheating problem is back again. My engine runs 85 to 90 degree C on most runs and I am at a lost with the cause of this problem. I have checked the timing and the carb adjustment and they checked OK. I am contemplating to advance the timing by 3 to 5 degrees to see if that will help. One thing I should mention is the fact that I had to use two head gaskets due to excessive shaving of the head in order to achieve close to the right compression. My TD is a Mark II type and at the time I rebuilt the engine I did not have an extra Mark II head. I have since acquired three Mark II heads with more meat on them and I may use one them if that is the cause of my overheating. Other than that, I am as much in the dark about this problem as you are. Good luck. Mac |
| MAC ASKARI |
| Mac, on a warm to hot day my TD has always run in that range. I wouldn't consider it to be overheating until pushing 95-again on a hot day or in traffic. I will say recoring my radiator definitely dropped the temp when around town or in traffic. My personal opinion is that 75 or below is too cold and maybe the thermostat was sticking open? If it did change that much just by the ignition problem changing the timing would be a good thing to try. What about fuel? Don't they put some wierdo additives in your gasoline that could make it run lean or hotter? So much variation from tank to tank here- on occasion a tankful will ping like it is kerosene. George |
| George Butz |
| Hi John , just a thought . Has your TD really overheated ? Did it actualy boil over or are you just going by the guage ? I checked mine once with a meat thermometer and found it to be a bit off the mark. Just a thought . |
| Alan |
| Alan, yes very hot. I checked the coolant temp when I got home with a digital gauge, the coolant is one of these with a ver high boiling temp. 180 degrees C according to the manufacturer so you are unlikly to get coolant loss through boiling or evaporation. But the temperature a few minuted after stopping the engine was 117 degrees C according to the digital thermometer reading in the top of the rad... |
| John Craggs |
| Perhaps a silly question, but...I have a moto-meter on the cap (no gauge inside cockpit, what is too hot. On 95%+ days I'll get red till right below the round clear circle. I've always gone by, if it isn't into that circle, it's OK. Is that right? Bob Doc |
| Robert Dougherty |
| Judging from previous posts, the Moto-meter doesn't go low enough to get an accurate reading? Believe an extension is attached to actually dip down into the coolant? |
| gordon lawson - TD 27667 |
| John, A completely different suggestion - had the same problem soon after I acquired my TD a couple of years ago. After checking rad and stat found it was the bob weights seized in the dizzie. Worth a look before tearing the head off (engine not yours) Good Luck Graham Smith TDC 7822 |
| G.D. Smith |
| Can I run a 160 degree thermostat in a TD? |
| RWG Goodling |
| I realize that it may not be able to restrict the area small enough, but has anyone ever used or tried a infra red scanner on tracing "cold spots" in an engine. The sort of scanner now coming in increased used during the virus crisis might work. Just a thought. Perhaps I'll try it and get one. |
| JK Mazgaj |
| This thread is 15 years old. Probably would have been better to just start a new one. But yes, you can run a 160° thermostat in your TD. Some may argue that a 180 is better since an engine runs more efficiently at hotter temperatures. I haven't found any negative issues running an XPAG a bit cooler though. |
| Steve Simmons |
| Steve, Didn't notice that!! However what was the "blue" liquid that was referred to. Any idea please? |
| JK Mazgaj |
| Jan - see this video: https://www.google.com/search?rlz=1C1GGRV_enUS751US751&ei=sUDAXoLiENqntQbn7LC4Cg&q=blue+%3Bliquid+carbon+monoxide+tester+automotive&oq=blue+%3Bliquid+carbon+monoxide+tester+automotive&gs_lcp=CgZwc3ktYWIQAzoECAAQRzoFCCEQoAE6BwghEAoQoAFQx2xY26wBYLquAWgBcAF4AIABvQGIAdYNkgEEMC4xNJgBAKABAaoBB2d3cy13aXo&sclient=psy-ab&ved=0ahUKEwjC_oPZkLnpAhXaU80KHWc2DKcQ4dUDCAw&uact=5#kpvalbx=_yUDAXoXoI4mPtAaPvbTgAg47 Tom Lange MGT Repair |
| t lange |
| Thank you Tom. Unfortunately link loads more about the music group etc than the product I'd hoped to research. Any way will continue to search. |
| JK Mazgaj |
| Jan - this is the stuff. https://www.nationaltoolwarehouse.com/Combustion-Leak-Detector-P20940.aspx?gclid=EAIaIQobChMItKvnxei66QIVRNbACh1N8gGfEAQYByABEgJShPD_BwE Tom Lange MGT Repair |
| t lange |
| This is the kit I use: https://www.amazon.com/s?srs=19838244011 It's pretty rare that I actually use it though. |
| Steve Simmons |
| Yesterday nine intrepid drivers attacked the road up First Peak past the Skunkawauken Falls. Shunkawauken Falls is a roadside 150-foot tall waterfall just outside Columbus (near Tryon and Saluda), North Carolina, on the twisting, scenic White Oak Mountain Road. Along the way, see some panoramic vistas as you climb 2,000 in elevation in five miles to the top of the mountain. Continue past the waterfall to complete a 11-mile loop drive. https://www.romanticasheville.com/shunkawauken.htm
The average grade is over 7.5%. The ambiant temperature was about 80F (27C) and the group included my '53 TD and Peter's '52 TD. Peter's TD has the original thermostat housing sans thermostat and mine has the new housing with a 185F stat. Both TD have the bypass blocked off and both have recently cleaned out radiators. Peter's TD cruises at 75-80C and mine at 85-90C. The drive includes several very sharp very steep up hill hairpins that put the car under quite a strain in 2nd but are still too fast to easily double clutch down into 1st. By the time we reached the top Peter was reading 95C and I was reading 110C (I have a newly reconditioned temp gauge from Nisonger, I haven't checked the calibration). I'm going to remove the stat to hopefully eliminate any flow resistance that it may be causing and, at the same time, calibrate the temp sender/gauge in a pot of water at known temps. Afterward, we'll attack the Skunk again and I'll let you know if there is any improvement. Jud |
| J K Chapin |
| Thanks Tom and Steve. Now on order. Regards Jan |
| JK Mazgaj |
This thread was discussed between 18/08/2005 and 17/05/2020
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