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My 1987 Turbo Esprit HCPI is overheating. I have just had the head gasket done, water pump refurbished, new rad a couple of years ago, the fans are working and we pressurised the system to bleed all the air out. I can drive it for maybe 20 minutes without a problem but as soon as I stop at traffic lights the temp climbs quickly and the coolant is forced out of the header tank. I am at a loss to what is causing the problem unless it is a cracked head. If the head is cracked my problem is do I get it repaired or try and source a HC fuel injected head which I would think are few and far between. Any suggestions would be welcome
 

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So it only overheats when you are stopped or going slow?

If so, sure fans are good?

Any chance the radiator fins got clogged in last 2 years (depending on your environment, might not take a long time).

Does it start overheating while just sitting in the driveway idling after starting from cold, or only after driving?

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Why did you have the head gasket done?

How did you pressurize the system to bleed the air out?

When it starts to overheat, are the hoses at the radiator hot?
 

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These cars are known to suffer thermostat problems, just ask brother Carbuff how many he's been through. There are two different operating temp t-stat's be sure you have the correct one.
A new one is about $25. from JAE, when in doubt throw it out. Even if it's new there is always the possibility it could be defective.

If it's blowing coolant through the tank it could be from exhaust gasses pressurizing the coolant system. NAPA and most autoparts stores sell a 'block tester' kit which uses a dye to test for exhaust gasses present in the cooling system. It's an expensive kit so you may want to take it to a garage that could do it for you.

I presume the water pump belt is tensioned correctly? Wouldn't hurt to check it. Stay away from 'Belt Dressing' as it could make the belt slip and ruins belts by softening them. When I replaced my belts I had to fuss around getting the proper tension I wanted. Too tight and you blow out the water pump bearing, too loose and it's not spinning the impeller fast enough to circulate coolant.

Coolant fans can also develope a 'drag'. Not enough resistance to cause a fuse to blow but not free enough to spin fast. What condition is the fan shroud in? The original plastic shroud is very flimsy and prone to breaking. It's held to the radiator with some very small screws and has a lot of weight. Steve at S&J Sportscars in the UK makes his own which is much stronger than the OE. I custom fabricated a mounting method which attaches the shroud to the front of the chassis using blank holes for 6mm bolts and not hanging from the radiator. It has much more support and is right up against the radiator as the original was.

Dumb question but I've seen it happen... the head gasket is installed correctly? If it's upside down it can obstruct the coolant passages and the gasket is a one way fit even though it may not look it. I take it the head bolts / studs were replaced? I'd have to get into my books but do they need to be 're-torqued'? Head bolts should alway's be replaced with new because on final torque the threads stretch. On the cylinder head jobs I've done it is alway's required to lubricate the bolt threads with oil to prevent galling.

Good questions Jim.

Hope this helps you figure out the problem.
 

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Wingless Wonder
1988 Esprit Turbo
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FWIW my thermostat issues were always "too cool". So while I'm no believer in any claim of longevity with regards to the t-Stats, I don't think your problem is this.


The first post seems to indicate that all the usual bases were covered.


BUT

I haven't seen the results of a Coolant System Pressure Test, though? I ask because the hoses on on the rad are difficult to install properly with the rad in place (don't ask me how I know this). Also the header tanks can sometimes rust out (pinhole leaks), and without a coolant recovery tank as fitted to the later models, the source of the lost coolant could be less obvious.

Was the HG done because of the overheating, or did this symptom appear AFTER the work was done?

Also, no mention of whether the heater core was bled. It's a common mistake to bleed the rad with the heater OFF, and then wonder where that air comes from.... :wallbang:


+++++++++++++

The second part of the OPs question is, can a cracked head be repaired? Hmmm...it's aluminum, anybody know of this being done successfully?
 

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Good idea to test thermostats in a pot of water on the stove if you are lacking confidence in them.


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The problem only exists when stopped. That is your clue. Definitely concentrate on the radiator fans, do the run, and do they move air. If it were an internal engine problem, the squawk would not be confined to times the car is stopped, probably would be worse under power.
 

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I put the car in because it was overheating which has been ongoing for the past couple of years. We removed the header tank pressure cap and fitted a cap with a pump on it that we could manually pump up the pressure. The heater was on during this process. It is a long drawn out job to bleed the cooling system but we got it done. It can idle for over half an hour without overheating. If you turn it off for a couple of hours and restart it within 10 minutes it overheats. The result of pressure testing the cylinders shows # 3 is lower than the others. I like the idea of the dye kit to test for exhaust gases. I have noted with the cap off of the header tank there is quite a lot of turbulence in the water. Is that common? The car is only driven during the summer within a city. I installed new spark plugs (Iridium)
 

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I keep coming to a sticking thermostat. How old is the thermostat and the coolant hoses?

When coolant hoses are old and heat up they can collapse on themselves which is why some hose makers used to put springs inside them if anyone remembers those.

It's a simple system not much different from anything else out there. If the system was air bound it would overheat very quickly.

I was using the Iridium plugs and felt they made my '87 engine run hotter so I went back to the stock NGK plugs. Are you going just by the temp gauge in the bin? Today you can buy infrared temp guns for next to nothing, I would invest in one and check temps all over the system.

If the radiator was replaced check the short hose on the top right, it has a 45 degree bend in it and is a fussy fit to get it right. This hose can kink if not installed correctly restricting coolant flow.

Check the heater hoses for collapse too because there are engine/water pump by-pass hoses. Not quite sure how to understand you are 'manually pumping up pressure' unless your using a pressure tester to pressurize the system and check for leaks. Doing this will not remove any air from the system plus blow out the heater core if your not careful.

I'm thinking perhaps you have a leak in the cooling system somewhere, causing it to lose coolant, become air bound and cause to overheat. Be sure all aluminium hose connections do not have any corrosion and the clamps are tight. Down in the right front side of the engine bay is an aluminium 'connector tube' which connects a 90 degree hose to the upright hose going over to the other aluminium tube and another rubber hose that connects to the upper T'stat housing. I had a very considerable amount of corrosion on that tube which was I presume was slowly leaking but would burn off when hot with no steam. When it's puking coolant and your topping it off you have no idea if there is a leak. Use a coolant pressure tester, watch the gauge and check all hose connections.

One way or another we will figure this problem out but before you get in any deeper $$$ wise... do the engine block dye test then we can eliminate that as a cause.

Sorry for the novel but without seeing the problem I can only list probabilitys.
 

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i haven't read all in detail, but did you start with the simplest first, replace the coolant tank CAP with a new one from JAE, so you know it is the right pressure cap.

I once put a wrong cap on my prior lotus 87 hci and had similar problems, all ceased when I put the right pressure cap on

And I would put a new one, b/c even if the one you have is the right pressure, it could have developed a leak
 

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Dear, WD,

If you haven't done so already I would check the air bleed hose that runs from the thermostat outlet line (aluminum) to the header tank. Mine was clogged, causing an air lock in the return and thus overheated.

To narrow down other cause(s) I would try the following:

1. Start the car "cold" with radiator cap off.

2. Keep checking the aluminum pipe or hose on the thermostat outlet side for heat indicating the thermostat is opening. You should also see expansion in the header tank or hot water from the bleed hose entering into there.

2a. If you suspect combustion is entering the cooling system, you can place your hand over the header tank cap bung and if there is pressure right away (on a cold engine) you have a head gasket/ cylinder head issue. (COLD ENGINE START-UP ONLY!)

3. Keep an eye on temp gauge and wait for the cooling fans to cycle.

4. Unscrew the radiator bleed that is located on the left top of the radiator to bleed any trapped air. Access is from the front boot.

5. If water is flowing and the fans are coming on but the car gets hot, you most likely have an internal problem.

6. If everything appears normal, replace radiator cap and keep an eye on temperature. If the temperature goes over normal, again, something internal.

7. If everything is fine, most likely air was trapped in the system.

One other option to add to this is to have the nose of the car facing down slope, either on a driveway or the rear of the car jacked up a bit. The idea is to get any air in the cooling system to rise to the highest point.

If you have had the cooling system drained it can be a PITA to get all the trapped air out. Once you do however its good to go.

Best,

Jeff
 

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My 1987 Turbo Esprit HCPI is overheating. I have just had the head gasket done, water pump refurbished, new rad a couple of years ago, the fans are working and we pressurised the system to bleed all the air out. I can drive it for maybe 20 minutes without a problem but as soon as I stop at traffic lights the temp climbs quickly and the coolant is forced out of the header tank. I am at a loss to what is causing the problem unless it is a cracked head. If the head is cracked my problem is do I get it repaired or try and source a HC fuel injected head which I would think are few and far between. Any suggestions would be welcome
Did you measure the liner "nip" when you changed the head gasket?

Did the old gasket show (read)where it had blown (If it had blown)?

910 heads arent really known for cracking so I doubt your head is cracked, but getting the liner heights above the block face correct is a critical factor in getting a good gasket seal on the head.
 

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Make sure all of the fans are turning and are turning in the correct direction and are fastened to the shaft of the motor. Make sure all of the ducting is there and properly installed. Since you say you had this problem BEFORE you did the head job and also after we can assume the head job did not correct the problem and it does not have anything to do with that. That said you could have caused a problem doing the head job that can contribute to overheating. I would suspect the radiator, hoses, water pump, thermostat. My guess is the problem is the cooling system has a problem and you cannot assume any of it is good without testing each part. The dye test is good to do if for no other reason that to eliminate a combustion gas leak from a cracked head or a leaky head gasket. I would also like to know why #3 cylinder is low. The motor should have a leak-down test now to see where you are losing pressure on #3 cylinder. Typically when you have a head gasket leak 2 adjacent cylinders will show high but it is also possible of one to be low and blowing into the cooling system. Or maybe #3 just has leaking rings. In any case I would be concentrating on the cooling system. I would also do a quick check on the timing. If it is way off that can overheat a motor. If you suspect the thermostat a quick way to test that theory is to remove it and run the motor and see if it still overheats.
David Teitelbaum
 
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