Help more problems - TR3A - getting hot!

[marko]

Hi all,

 

The saga continues and your help would be apprecited again!

 

After solving my nasty oil leak (rear crank seal, unleaded conversion & core plug - see massive thread) my TR3A is getting overly hot.

 

It has a normal engine fan and a kenlow!! but still gets three quarters hot and then spits coolant all over the floor once the engine is stopped.

 

The Kenlowe is running constantly and the radiator, block and waterpump have all been changed / pressure cleaned. still getting very warm. The gauge has also been swapped with 2 others that I know are accurate.

 

Is there anything else that could be causing the problem.

 

I've had it running with and without the thermostat - no difference....Help!

[whiteone]

Are the top and bottom hoses and the whole of the radiator getting hot?

[marko]

yep - I think so - will check

[marvmul]

Paul Richardson has published some magazines 'Triumph over Triumph', about 5 years ago. In one of these magazines, he has written an article about overheating problems of the sidescreen TR's. He says that most of the persistent and unsoluble overheating problems were caused by reduced heat transfer from water jacket wall's to the coolant or from the coolant to radiator core : the reasons are the build-up of limescale in the engine and the radiator, but also the presence of only a little amount of oil in the coolant(oil can get in the coolant by headgasket failure or from outside)  can cause overheating problems.

If the engine and radiator are really clean, and no headgasket leak is present, and all other obvious causes are excluded, a cracked block or cylinderhead are possible.

He advises to look at the exhaust for steam or water, check the fanbelt, sticking thermostat (sticking shut intermittendly sometimes). Fluctuating, slowly rising temperature are mostly a sign of the onset of headgasket failure, as are air bubbles circulating in the coolant. So if there is no beginning or minimal headgasket failure, most of the 'incurable' overheating problems are caused by lack of cleanliness (limescale or oil in the engine and radioator) according to this experienced son of Ken Richardson.

[CP62]

Four other possibilities:

 

Ignition - if it's too far advanced, the engine will tend to get hot (does it pink a lot?)  Can be caused by old points that have eroded enough to open the gap a bit, effectively advancing the timing by enlarging the dwell.

 

Fuel - if it's too lean, it will tend to run hot (when last tuned?  does it fluff when you try to accelerate hard?)

 

Head gasket - leaking from a combustion chamber into the waterways - does it run a bit rough, produce white 'smoke' (actually steam) from the exhaust?

 

Water pump - but I must say I've never come across one that appeared OK but wasn't moving the water round.

 

Finally, are you sure that the block and radiator couldn't be restricting the flow?  If the rad is new, that will be OK, but blocks are very good at building up solid sludge around no4 and to a degree no3 liner, which causes the rear of the block to get very hot.

 

All the best,

 

CP62

[marvmul]

Water pump - but I must say I've never come across one that appeared OK but wasn't moving the water round.

Some months ago I had two consecutive new waterpumps on wich the impeller was loose. It wasn't obvious when installing them, and when checking afterwards soms force was needed to move the impeller on the shaft;

I had a lot of overheating trouble before I found the cause;

I suppose that, when newly installed, the impellers move somewhat slower than the shaft, working looser in this way, and on my engine the impellers moved on the shaft to the rear, in the end they  touched the pumphousing and then almost stalled. It started with overheating slowly, we went through all possible causes. In the end, the engine overheated from cold in a couple of minutes; when I removed the pump for the third or fourth time, I noticed that the impeller had moved rearwards on the shaft. I bought a new one which had the same fault.

[jonlar]

Hi Marko, have you tried running without a thermostat - if not, I'd suggest you give it a try, you'll be able to check water pump flow - also is the pressure cap OK and working to correct pressure - lower pressure = overflow?

[Nigel Lay]

Ref Jons letter - don't forget to restrict the flow through the bypass hose otherwise virtually non of the hot water will go round the rad. I have run TS952 stationary while sorting out the carbs for over 40 mins. in the middle of the summer with no sign of overheating at all. Standard rad. & fan with skirted 82 degree thermostat.

Nigel

[Mychael]

Marko, a simple thing which can be overlooked, is the electric fan running the "correct" way so it's pushing (or pulling) air from outside the car to inside ? sounds like an obvoius thing I know but if it's like some fans the blades can be reversed for inside or outside mounting. I got caught with mine when I went from a postive to negative earth and the fan then ran backwards, took me a bit to work out why the car was running hot.

 

Mychael

[sforster]

Marko,

one thing that is often over looked, is there a funnel around the radiator thus pushing air through the rad and not all around the engine bay?

Simon.

[Don Elliott]

If you are only spilling the water/antifreeze mix when you stop, it may mean that you are overfilling the radiator.  Remove the filler cap and you should only fill the fill-trough so you cqn see about 1/2 inch of liquid down at the flat bottom of the filler trough.  Filling more than this will spill the excess out when you park after a hot run.

 

Don Elliott, 1958 TR3A

[gnotte]

Hi,

have you read the "uprated water pump" topic in the Tr4 forum and especially the post from Buly.

As you replaced the head and probably drain water, you could have encountered this problem too.

Guy

[Richardtr3a]

My 3a was hopeless and would run hotter the faster you drove. this was after an engine rebuild by an old fashiones firm in brighton. After two summers I took the engine to Darryl at Racetorations who discovered that the liners were not at the correct heights before the head went on. Once this was cured I carried on with the improvements. Now I have a Kenlowe in front . This was initially blowing the wrong way but by swapping the leadsover, it now blows back through the radiator. I have a cap on the radiator without the springand seal and the overflow take off is connected to an expansion bottle, next tomthe washer bottle. This allows you to fill up to the top of the radiator neck and expansion and contraction is available. There is a 4 lb cap on the expansion bottle. I also have the ducting fitted to channel air into the radiator. I had considered my radiator to be in good shape until a new up rated core was fitted and the needle now rarely passes the center point on the guage. Southern Radiators in Chichester 01243 778242 £176.25 in 2004

However in the late sixties I ran the car without ducting, without an electric fan and with some soldered waterways following damage. It never overheated is spite of London traffic and when the heater stopped working we knew that the water level had dropped. There was corrosion in the top face of the block. I suppose that the old 5 star petrol was different.  

[julian c]

1.How long does it take to overheat from when its stone cold?If under 10mins,water pump

2.Is it more likely to overheat at higher revs?If yes,water pump,blocked rad is possible.

3.With the fan running,check that consistent hot air is coming off the fan.If not,water pump,thermostat is possible.(depends on where the fan swith is)

4.Is overheating intermittent?Is bottom hose cold(er)only when it gets hot?If yes,water pump,occasionally thermostat.

5.Does the engine run lumpy when you first start up from cold and clears after approx 15 secs?..if so...

Can you borrow a coolant pressure tester?If so,from cold,start engine,rev around 2500 rpm for about 10 secs...if any pressure builds up at,then head gasket/liner problem.

6.Does coolant come out when engine is running?if yes,check rad cap,check pressure in cooling system.If not,then possible water pump impeller.(saw this on a KTM bike this week)

Water pump faults can be very intermittent and frustrating to pinpoint.Never assume its ok just because its new.Actually have it in your hand and check the impeller is not loose on the shaft,the correct distant from water pump body and check there are no scrape marks on impeller indicating a restriction of sorts.

If you can tell me more details of how it overheats,I may be able to offer some specific suggestions.

 

Okay...............Im off to bed now........

 

[marko]

OK what happens is this.......

 

Car runs perfectly - the temp gauge gets to just under half way (without the Kenlowe) - I take it for a 30 min run - performs beautifully - bring it back - let it tick over - temp gauge still fine then it starts to boil the water (temp gauge still midway and the temp gauge is defintately working correctly -as I've tried 3) - burbles and spits water out of the overflow pipe. 4lb rad cap fitted!

 

It seems to me like it has a "hot spot" in the engine somewhere although it has been cleaned with caustic twice now.

 

The head has been removed and the gasket is perfect - so the head is going for a pressure check on Monday morning.

 

The water pump looks perfectly ok and the fan belt is tight.

[BrianC]

Assuming the radiator cap and seal are OK, it sounds like a classic case of overfilling.  When it finishes spewing water, let it cool down, note the level of water left in the header and then take it out for another run.  With luck, you should find at the end that the level is up to the top but not overflowing.  When cooled again the level should be as noted before.  I have made this mistake in the past with TR3A headers and also with the TR4A expansion bottle.

[Mychael]

You can also safely use a 7lb cap without trouble provided your rad is in good condition.. I've used a 7lb for years without problems.

 

Mychael

[John Morrison]

Bill Piggott did a piece on this for TRAction a while back, seemed to cover all the probs, will dig the relevent mag out if you want,

john

[marko]

Hi Guys,

 

It seems to me having read the thread in the TR4 section that I am getting a hot spot due to a partial blockage around the rear cylinders - the head is being pressure checked tomorrow to see if there is a hairline crack causing pressure to build but it seems more and more likely that it is a build up of **** in the engine which stops the water circulating properly.

 

I'll keep you posted - it's definately not being overfilled - it is shooting out steam from the overflow pipe!

 

Hey hum!

[Guest chris jameson]

I had the same problem as marvmul, with my water pump.  It looked fine, and was a brand new repro.  The trouble was that the impeller was turning on the shaft, and not pushing enough water through.  This in turn was causing my overheating problem.

 

I drilled the impeller and shaft, and fitted a roll pin, which fixed the problem.

 

Cheers,

 

Chris

[Mychael]

A lot of the repro stuff is junk. Okay if you only plan on useing the car very infrequently on shorter runs. I've had 2 pumps fail from bent shafts from new.

Only solution was to "bite the bullet" and get a custom overhaul done.

Mychael

[marko]

Well - Thanks for all the information - I think the problem may be cured (fingers crossed)

 

The head was removed (again) because when it was getting hot I noticed tiny bubbles escaping from the cylinder head bolt tops (where the nuts fit) - so I assumed it may be forcing air from the head gasket into the waterways (suspected cracked head or faulty headgasket!)

 

The head was pressure checked and fine but one thing the that the company mentioned was "what type of head gasket are you using" - I had a copper gasket fitted, they said they had skimmed the head for a composite type gasket not copper type - so they re-skimmed for a copper type!

 

Whilst the head was off I got a coat hanger and poked it down all the little holes and crevices to make sure there wasn't any obvious blockages around the liners or the rear cylinders, it was also filled with caustic soda for the 3rd time to try and breakdown some more crud!

 

Head back on, water back in, head torgued down - hey presto - road tested for 30+ miles (without the kenlowe) left it running stationary - temp got to just under half way!

 

Please pray for me!

 

[rudi]

I'd like to clean the waterways of my engine. (engine in situ, with head on). How should I proceed and what product should I use?

Best wishes to all and happy TR-ing in 2006. Rudi

[Guest Geoff Carter]

Simple things first. Check you've got the right rad cap and the spring loaded cap fits tight against the lower header tank. Loose fit means no pressure in the system.

 

I had the same problem which was caused by a dodgy stat. If you drive in summer only remove it.

 

Don't overfill header

 

Check ignition timing. Retarded engines lead to hengines running hot.

 

Geoff Cartr TR2 TS1923 RYD 761