Lord Flashart Posted August 19, 2012 Author Report Share Posted August 19, 2012 Cheers Menno. I think the water pump will be my first port of call. I suppose the best course of action is a new housing and pump? It's pumping at low revs as it'll shoot water at the garage ceiling if I remove a hose, but I'm guessing it's cavitating at high rpm, which I can't really test, Paul Quote Link to post Share on other sites
Lord Flashart Posted August 19, 2012 Author Report Share Posted August 19, 2012 (edited) Just an after thought. If the pump is cavitaiting, is it due to the pump-housing clearance? That's something I can check. Any idea what it's meant to be? Paul Edited August 19, 2012 by Lord Flashart Quote Link to post Share on other sites
Lord Flashart Posted August 20, 2012 Author Report Share Posted August 20, 2012 (edited) Home now and back tinkering. A few observations. My gauge has 70 next to the needle mid range position not 80 like MikeF suggests. Do I have an incorrect guage? The ambient temp is a little lower tonight but is still high twenties, but running the electric fan constantly seemed to control it slightly. I'm thinking that points to an airflow issue even at high speed. I'm wondering if the gauge is reading a little high as the gauge needle was just about the normal sector, but my electronic thermometer pointed to the radiator next to the inlet port only read about 72degrees. Can I adjust the gauge? I also noticed on shut down there is a brief gurgling noise from the cooling system. Does this point to an airlock or the dreaded leaking head gasket? Tomorrow I'll do another high speed test to see if the problem persists in the days heat. It's forcast to be 35 tomorrow so if it's going to overheat it'll be then! Edited August 20, 2012 by Lord Flashart Quote Link to post Share on other sites
Bully Posted August 20, 2012 Report Share Posted August 20, 2012 I had a similar problem many years ago, which eventully resulted in my TR4A constantly overheating. Turned out to be a blockage between the No 4 cylinder (nearest the battery) My understanding goes that when you change the coolent, you need to drain the radiator, and also the engine block. Over the years, it would appear that most people only use the drain plug under the radiator, so sediment builds up in the block. With forward motion, this sediment goes to the back of the engine, and blocks the water ways. I fould I could actually take the drain tap out of the engine block, and no water would come out even when full. To get me running again, I removed the cyclinder head, and manuafactuered a small spoon out of a long thin rod, and scooped out the ****. A couple of years ago, I did a full rebuild, and made particular attention to clearing this area. Remember to always drain both the block and radiator when changing the coolent. Cheers Bully Quote Link to post Share on other sites
North London Mike Posted August 20, 2012 Report Share Posted August 20, 2012 Banff: Every time I go its covered in snow , still spectacular though ! Quote Link to post Share on other sites
Andrew Smith Posted August 20, 2012 Report Share Posted August 20, 2012 Banff: Every time I go its covered in snow , still spectacular though ! Every time I go it's full of Japanese......... Cheers Andrew Quote Link to post Share on other sites
Ian Vincent Posted August 20, 2012 Report Share Posted August 20, 2012 "It's only four hours from home so we come here quite a lot." Paul This neatly summarises the difference in attitudes on this side of the Atlantic. A four hour drive will take me to London - definitely not 'only' and I don't want to go there quite a lot either - even tho' I did live there once. Rgds Ian Quote Link to post Share on other sites
Lord Flashart Posted August 20, 2012 Author Report Share Posted August 20, 2012 (edited) The attitudes are totally different, but everything is so far away, it's a necessity. It took some getting used too though. In Newcastle, my home town, everything you need is within an hours drive. Cheers for the suggestion Bully, but the block is as clean as whistle. I only rebuilt the whole engine a few thousand miles ago! Banff was nice because it was cool! Only 18 degrees during the day and down to 4 during the night. Here at home it's 35 during the day and it gets almost unbearable, hence the frequent trips into the mountains for cooler weather! On the subject of the japanese tourists, we thought we were going to see one killed by a bear on Friday. We were up the Ice Fields parkway and he had stopped to photograph a black bear at the roadside. Only stupidly he got out of his car and tried to get close to it. The bear got a bit annoyed at him and started grumbling at him and then charged. Lucky for him his car was only a few feet away or he'd have been mauled. People forget these things are wild animals. Fun to watch though. Paul Edited August 20, 2012 by Lord Flashart Quote Link to post Share on other sites
RogerH Posted August 20, 2012 Report Share Posted August 20, 2012 (edited) Hi Paul, A while ago on holiday in Los Angeles a tour guide warned people of the quite common rattle snakes and the odd bear. She asked the question "which one would you least want to meet?" Most people said the rattler. The guide quickly pointed out that rattlers couldn't climb trees but Bears can go anywhere - and quickly. Roger Edited August 20, 2012 by RogerH Quote Link to post Share on other sites
ChrisR-4A Posted August 20, 2012 Report Share Posted August 20, 2012 I have had a similar problem since the slightly tuned engine was fitted. It was suggested i clean the rad using Furnox, which is meant for house central heating systems, put the whole bottle in rad off car and top up with boiling water. Shake about and leave for 2 days. Weigh rad before you start andthen after. Mine was nearly a pound lighter, some have been known to be upto 3 lb lighter. Also changed thermostat for a 76deg one. Car now runs about 5 mm lower on gauge , near the lower line of the normal. Also chech the rad cap, my previous one let water out when hot but not back in. Quote Link to post Share on other sites
LGFromage Posted August 21, 2012 Report Share Posted August 21, 2012 Did you tighten the distributor clamp bolt sufficiently after you timed the engine? If not the distributor will turn and the timing will suffer making the engine run hot, especially at higher speeds. Tim Quote Link to post Share on other sites
Lord Flashart Posted August 21, 2012 Author Report Share Posted August 21, 2012 Cheers guys. The dizzy is definately tight and the rad is also brand new. I'll keep looking!! Paul Quote Link to post Share on other sites
TorontoTim Posted August 21, 2012 Report Share Posted August 21, 2012 Maybe it's just high revs in HOT weather...? Mine was certainly a little marginal on fast/high rev running in the 30+ heat that we had in the past few weeks. I had a run down from N Ontario on Sunday evening: same engine conditions (constant 4000rpm for up to an hour), but ambient temp about 22 or something, and it ran a tiny bit cool. Quote Link to post Share on other sites
Lord Flashart Posted August 21, 2012 Author Report Share Posted August 21, 2012 (edited) I think you are right Tim. Maybe I have to lighten my right foot in 35 degree weather! I'll still fit an oil cooler this winter to see if it makes any difference. Paul Edited August 21, 2012 by Lord Flashart Quote Link to post Share on other sites
graeme Posted August 21, 2012 Report Share Posted August 21, 2012 Paul, I had an oil cooler fitted to my car and it made no difference to the cooling problems I was experiencing at that time. My engine was clean inside, new radiator, etc but still problems. I took advice from Ian Cornish and fitted a header tank (from aTR7) as is the norm on modern cars and all cooling issues were solved. The oil cooler is now history! If you look at the radiator in relation to the thermostat housing, you will notice that it is impossible to keep the housing full of water and I suspect the temperature sender is likely being uncovered during your periods of high revs and starting to measure the temperature of the metal by conductivity. Anyway, the header tank cured it for me and although our temps are slightly cooler about 30-32 degC, the temperature never moves during driving and my electric fan only comes on if stood in traffic for any length of time and I never use any water. Even when we were in the South of France with temps of around 38 degC we had no problems with water temp. Save your money on the oil cooler and get a header tank. Cheers Quote Link to post Share on other sites
Lord Flashart Posted August 21, 2012 Author Report Share Posted August 21, 2012 Interesting Graeme. I remember seeing your header tank on the bulkhead of the car. I'll stick it on the list of things to fit this winter. Paul Quote Link to post Share on other sites
Lord Flashart Posted August 21, 2012 Author Report Share Posted August 21, 2012 Just looked and the TR7 tank seems hard to get hold of. I might try an MGB tank. I'm sure I've seen pics on here of one mounted on the inner wing as high as possible. Paul Quote Link to post Share on other sites
LGFromage Posted August 22, 2012 Report Share Posted August 22, 2012 Having filled the radiator do you half fill the overflow bottle? If not every time a hot engine is switched off some of the water disappears as steam/vapour. An air lock then develops in the cooling system as the water cools, getting worse over time. With a half full overflow bottle water is sucked in to the radiator rather than air. With this arrangement there is no need for a header tank Hope this helps, Tim Quote Link to post Share on other sites
Lord Flashart Posted August 22, 2012 Author Report Share Posted August 22, 2012 Hi Tim. Mine is a really early 4, so it has no overflow bottle. Just dumps in the road. Paul Quote Link to post Share on other sites
Lord Flashart Posted August 24, 2012 Author Report Share Posted August 24, 2012 It just occurred to me. I wonder if the car was leaning out at high RPM due to the split in the fuel pump diaphram as discussed in my other thread. That would explain the over heating when going fast. Might have cracked it. Paul Quote Link to post Share on other sites
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