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TR6 Continuing Saga of TR6 Temp

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jerrybny

jerrybny

Jedi Knight
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I posted about a month ago about my Temp gauge being at about 3/4 mark when its hot and humid. Many suggestions were made. Here is what I've done:

1)New Temp Sending unit 2)160 degree Thermostat
3)Checked timing-OK 4)Balanced Carbs and adjusted
mixture
5)Installed 185 degree thermoswitch for 16" electric fan
6)Check vavlve clearances - OK
7)Replaced Temp Gauge with spare
8)Replaced voltage stablizer with spare
9)Checked water pump belt tension - OK I can see the water flowing once the thermostat opens

I used an infrared Thermometer and the fan is coming on when the upper radiator hose is about 185 degrees. It stays on for about a minute and then shuts off. It continues to do this as long as the car is running. The temp gauge is between 1/2 and 3/4's mark when the fan comes on. I haven't seen the temp go above 195 on the upper hose or the radiator.

So after that long winded explanation I am wondering if I have missed checking anything or is everything ok. It just bothers me that the gauge is sitting between the half and 3/4 mark when idling. When I am driving it comes down to just a hair over the half way mark. Am I driving myself mad over nothing??

Has anyone else with a TR6 ever checked the temps at different locations? Such as the exhaust manifold, block, etc. If so I would be curious what they were so I have something to compare against. I want to thank everyone who has responded or is going to respond.
 
Geez, Jerry, I think you have it about spot on. I drove mine today in 97 degrees. At speed it hovers at about the 2/5ths (got that) area. The fan comes on as soon as I get into traffic and the needle reads at about 3/5ths. Never goes over that. I have no crank fan and have the aluminum rad with 16" puller. Have you tried Water Wetter? Might get a couple of degrees cooler and a few bucks poorer. I use it but don't know why.
Another thingy to try is VB markets an ABS fan shroud that fits behind the radiator. I used it for a few years and it seemed to help alot. Funnels the air and directs the crank fan better. I really would recommend trying it. Mine ran much cooler with this device but that was before the engine mods, AL rad and puller fan. A bonus is it keeps debris off the underside of your bonnet that the crank fan invariably slings up there. I would recommend this as a next trick. Not expensive, well made and easy to install. May have to trim it a bit to fit underneath the rad hose at the top of the rad but other than that a well made item.

Bill
 
Bill, I already have both the front shroud and the from VB also. The only thing I left out was that I ran the Zerek Flush for about 5 hours before backfflushing the system and refilling it with a 50/50 mixture. I guess I can try the water wetter. What the heck its only money right? LOL I wonder if its possible that I have an air pocket somewhere in the system. When I filled the cooling system I put the front end higher than the rear. I read somewhere that that helps prevent air pockets. Not sure if its true but I did it anyways. I guess I would wonder how to get rid of an air pocket if I have one. This is driving me crazy. If I hadn't given up drinking I would have a double right about now. /ubbthreads/images/graemlins/thirsty.gif Well thanks Bill. Hopefuilly someone will chime in that has a IR thermometer and has measured different engine spots.
 
It’s hard to clean the water passages inside the block when it's together. I wonder if you have some resistive blockage? What type of muffler do you have (could it be some what clogged?)? Are any of the exhaust pipes partially blocked? Retarded timing can make it heat up as well as an overly rick carb mixture.

After all of that, you can worry about proper oil flow. Do you have cam bearing? Do you have oil seals on the valves? Are you running an oil cooler? If not, it would be an asset especially if you run an after market one and a larger spin-on oil filter… actually increase the volume of circulating oil. Good luck.
 
Call me crazy if ya want but I am half way finished putting the stock fan back in. All I have to do is put in the radiator and fill it up. I plan to use the electric fan as a pusher. If any of you recall my original problem was the car approaching the 3/4 mark when stuck in traffic on a hot day. Back then as long as I was moving it stayed near the 1/2 mark. Since removing the stock fan and putting the puller fan in I have a hard time keeping it away from the 3/4 mark. When driving it is between 1/2 and 3/4. So I figured what the heck its raining all week here in NY and its only about a 4 hour job to do the switch. I'm hoping that the stock fan will keep it cool while driving and when I'm in traffic the electric fan should kick in at 185 degrees and help cool it back down. Hope I'm right. Maybe the fan I got isn't the best one on the market. It wasn't a SPL it was a Hayden. The baby just seems to like to run on the warm side. Thanks for all those that made suggestions. Well keep you posted on what happens. /ubbthreads/images/graemlins/cheers.gif
 
Jerry,
I know you broached this subject before but what color are your spark plugs? If they are really white or white/tan then you might be running too lean a mixture, which would make it run hot as heck. Try running on the richer side of lean and see what happens.


Bill
 
They aren't white. In fact they were leaning towards the black side that is why I readjusted the carbs and timing
 
Jerry
I had a similar problem with one of my other cars. I did everthing but replace the radiator. I didn't replace it because it was only two years old. Come to find out the radiator was the problem. Changed it and all was good.

Bill
 
HMMM its a brand new radiator. Wonder how you tell if a radiator is bad. It would suck if I bought a new radiator from VB and it was bad.
 
Jerry

Sorry I missed the part in your post where you said you put in a new radiator. If the car is running under 210 deg., this should be no problem. Is it getting so hot that coolant is coming out of the overflow tube? When you shut off the motor, do you hear the coolant boiling?

Bill
 
Jerry
Quit worrying, sounds normal to me. When coolant temp. starts to go over 220 deg on a hot day, then you can start to worry (not always).

Bill

Bill
 
Hi Jerry,

I agree with Bill. If anything, you have an inaccurate temp gauge in your dash (they were never all that accurate to begin with, not a lot better than an "idiot light").

The IR thermometer should put your mind at rest. Most TRs seem to run best on the slightly cool side, say 185-200F, but 210 or even 220F is where you should start to get concerned. Your car sounds to be well within the "correct" range, no matter what the dash gauge is telling you. Besides, there is such a thing as *over-cooling* too, ya know (and, modern cars often are designed to run hotter, BTW)!

The problem with "pusher" fans is that they inevitably block some of the air flow and are more exposed to the elements when driving. A good quality "puller" fan will draw more air through the rad and is somewhat protected behind the radiator. But, if a "pusher" combined with the stock crank-mounted fan works for you and your style of driving, great! This sort of setup does provide a bit of useful redundancy, should one or the other fan fail for any reason.

/ubbthreads/images/graemlins/cheers.gif





Drive it, enjoy it.
 
I've never seen the anti-freeze get above 195. I used an IF theornmeter and pointed it at the anti-freeze as it went by. The only thing that puzzles me is why last year the gauge stayed near 1/2 except when in traffic. But it sounds like I'm probably alright The car is never driven except on sunny days so I'm not to worried about the pusher fan being exposed to the elements. BTW with the stock fan back on it takes a whole lot longer for it to go past the halfway mark. At about half way between the 1/2 and 3/4's mark the electric fan comes on. So putting the stock fan back on definitely helped a little. Like I said it is a Hayden fan. Maybe they don't pull as much air as some of the better ones and thats why it had trouble keeping the engine cooler. Just a guess though. Thanks
 
Sorry Jerry, but I think you should find out what is causing the high temp. I don't believe it is erroneous readings, I think you are running too hot. Gauge and sending unit changed out and the same reading before the change is too much for coincidental. If it use to run at the mid point, something has changed. Running too hot will certainly shorten the life of your engine.

Check the type/brand of the thermostat you installed and the position of the therostate (I can't recall if it will fit up both ways). They don't cost much so a change out may be worth a try. Also, a drop in a pot of water with a cooking thermonitor to ck its operation can ck the status (be sure mama ain't around when you try this). Back flush the block, pull the plug on the side of the block (looking for rust); back flush the radiator, look for any build up of crud on the tubes inside the radiator; GET PROFESSIONAL HELP if nothing else works. You did say you changed out the water pump for a new one, one with full wings on the impeller, right?
 
I have had a 'bad' new waterpump before. Got a another new one from a different supplier and when it proved to work sent the bad one back to who supplied it. Explained it all over the phone and got a return authorization.

/ubbthreads/images/graemlins/cheers.gif
 
Your experience with a defective water pump rings a bell. It reminds me of "Big Daddy" when he only used tried and proven (tested/used) parts.
 
POSITIVE PROGRESS !!! I back flushed the cooling system again today. This time when I opened the block drain plug the water only dribbled out. So I took my hand coat hanger and worked in and out and all of a sudden the water started pouring out. So it looks like the passage may have been partially blocked. So I backflushed 3 more times. The temp was 85 and humid today. After flushing it I started it up with just water in it. It took 8 mins to reach the half mark. It took 15 mins for the electric fan to kick on when is set to turn on at 185 degrees. It ran for about 5 mins and then shut off.

I'm assuming 15 mins to reach 185 degrees idling in the sun is ok. The gauge never went past halfway between the 1/2 and 3/4 mark. I figured I run it for awhile and see what happens. I'll probably backflush one more time after putting some miles on it. What do you guys think?? I want to say many thanks to all and a special to those that said to continue to try and find out why it was running hot all the time. I know this thread has become quite long and its a testament to TR owners that I never once got flamed for asking stupid questions or asking the same thing many times. TR owners are the best. /ubbthreads/images/graemlins/england.gif
 
[ QUOTE ]
POSITIVE PROGRESS !!! I back flushed the cooling system again today. This time when I opened the block drain plug the water only dribbled out. So I took my hand coat hanger and worked in and out and all of a sudden the water started pouring out. So it looks like the passage may have been partially blocked....

[/ QUOTE ]At risk of sounding sarcastic or flippant...how many times have I posted here and on other lists about doing this? I should total it up sometime. It's a trick I discovered a long time ago. Best of all, it's cheap. Second best of all, one will almost always gain from this if the cooling system has gone more than a year or two without attention!
 
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