Engine and Transmission Tech

We have a 1963 Buick 215 engine in my son's car. We bought the engine from ebay last year. It runs fine, but it overheats very badly. Even after about 5 minutes of idling, the coolant temperature can exceed 220 degrees F.

We put a new water pump on the engine before installing it into the car. I also tried taking the thermostat out, but it still overheats.

My specific question has to do with cooling passages. The engine has an Edelbrock Performer 2198 intake manifold. We have noticed that there are cooling passages in the heads, at rear, but there is no matching port at the rear of the Edelbrock intake manifold. Is this usual? It seems like some of the coolant would just sit there at the rear of the heads and not have any place to go.

Can anyone answer whether this could be the cause of the overheating? Or perhaps suggest another cause?

Welcome to the BritishV8 forum, Paul!

The lefthand and righthand cylinder heads are identical - you could remove them and swap them side for side - and therefore they have cooling ports at both ends. Buick and Rover blocked off the rear ports with their stock intake manifolds. Your cooling problem is undoubtedly elsewhere.

Perhaps we can help you track it down. The more information you can provide, the better. What vehicle have you installed the engine in? What else have you already checked or tried to fix the problem?

One of the first things I'd check is fuel mixture. Is it way too lean? What is the size and condition of your radiator?

Thanks, Curtis!

This motor is installed in a 1963 Oldsmobile F-85 station wagon (yes, not exactly a British sports car).

It did not overheat with the previous motor (also a Buick 215). We had to take out that motor due to possible oil starvation, and valvetrain mayhem, involving an escaped pushrod.

The radiator is the same as before, though my son did spray some paint onto it, which probably is hurting us as far as heat transfer away from the cooling fins. We will be getting that remedied. The radiator is a stock Olds F-85 radiator. I would suspect it, except that this problem did not occur earlier last year, before we swapped motors.

We put a new water pump on the motor, but I'm thinking it may not be pumping very well. If I take the radiator cap off and watch the opening while the motor idles, I don't see as much fluid streaming in as I would expect. So, perhaps there is a mismatch somehow with the new pump, though visually it seems the same as the one we took off, and also the same as the one on our previous engine.

I tried taking the thermostat out, but that didn't change the problem. I thought of the possibility of a faulty water temp gauge, but it is the same one we used with the previous engine, and the motor DOES seem very hot to the touch after idling just a short while.

We could be slightly lean on the fuel mixture, I suppose. But I don't think we are too far off, because it has no problem idling smoothly.

Paul, Same heat range of spark plug ? Identical initial timing and curve ? Identicle compression and octane ? Does radiator need a back-flush ? Fan shroud installed ? Possibly getting in-audible preignition/detonation ? Did removing the thermostat change the running temperature ? Good Luck, roverman.

Thanks, roverman.

Well, so much is identical as with the previous engine. I suppose we could flush the radiator. We simply drained it and put all new coolant in.

The fuel octane is the same, but I think that this is a lower compression engine (old one was 10.75 to 1, if I recall).

We've never had a fan shroud on this car. I'm not saying it mightn't help; it's just that the overheating is so excessive and so fast, that I think something very major must be wrong/different compared to before.

Timing could be off a bit, but it pulls good vacuum, so I don't think it can be far off. Using the same distributor as before.

Removing the thermostat did seem to make it take just a bit longer to get up to the really hot temp. Right now, I'm thinking we are not really pumping coolant through the radiator at any decent rate. The radiator does not get very hot. I'm suspecting the water pump. Someone told my son that the front cover, which mates with the pump, can wear and cause pumping losses.

Does your lower radiator hose have a spring in it to keep it from collapsing and cutting off coolant flow under vacuum? Are either of the hoses kinked?

From your descriptions, it's easy to imagine that the water pump is a problem. It's possible you got one that was wrongly assembled. Did you keep the old one around? If so, you could easily remove the new pump and compare them...

On some cars, poorly conceived heater plumbing ends up functioning as a radiator bypass circuit. You might want to have a look to make sure your heater plumbing is correct... or at least temporarily block that flow. (IMHO, heater cores don't usually appreciably improve overall cooling capacity.)

Spray paint on a radiator won't have much effect.

I haven't heard of Buick front covers degrading to the point that coolant is impacted... but if you're worried about that they're relatively cost effective to replace and when you replace them you can go from an original-type "rope" front seal to a modern-style neoprene seal. Of course the oil pump is built into the front cover. Bonus: new oil pump gears will come with the new cover. More info here: [forum.britishv8.org]

By the way... you mentioned removing the thermostat. I don't recommend running without one. They're really easy to test! Just put your thermostat in a pan of water on the kitchen stove and see that it opens and closes appropriately. They vary rather a lot from brand to brand, etc.


note: back in this thread I reported:

Quote:

I forgot to mention that I tested two thermostats while I had the water boiling: the old thermostat from the Rover (probably OEM, marked made-in-UK) and the old thermostat from my Buick engine (aftermarket, marked made in USA, but I don't recall by whom). At boiling, the Rover thermostat was barely open whereas the "Buick" thermostat was open about 1/4". I'll discard the Rover thermostat and instead use the American one.

Edited 1 time(s). Last edit at 04/10/2013 03:16PM by Moderator.

Remove fan belt and radiator cap, rotate water pump with an air or electric tool counter clockwise then clockwise and see if there is any difference in flow. Might have a reverse rotation impeller for serpentene drive. Just a guess.

Leakage of exhaust into the coolant, possibly due to a blown head gasket, could also cause overheating. That sort of overheating is typically worse under load than at idle. I've never had it done, but I understand that most any good radiator shop can check for combustion products in the coolant.

I would be inclined as well to say that you have a water pump problem. If the rad is staying cool that indicates a flow issue. The most likely would be a serpentine pump on a vbelt drive, like john said.
Tuning problems (fuel mix, timing etc) aren't going to have much effect @ idle.
A head gasket or cracked block problem can show up at idle and will generally "push" all the coolant out of the motor. It also shows up as a short term miss fire on a cold start. The coolant that leaked into the cylinder shorts out the plug until it dries up.
You can get dip strips to check for hydrocarbons (exhaust) in the coolant at most auto stores. Or just give the coolant a sniff. If it smells like exhaust, then you've got trouble.
Hope that helps
Cheers
Fred

Here's a quick snapshot of a Buick/Olds 215 water pump impeller.

(note that it's non-directional)

Sorry Curtis, but it is totally directional.
The impeller is gender neutral, but the scroll of the housing is not.
Adding a serpentine impeller to this mix would result in a hydraulic stall.
Possibly/probably not the cause but with old rebuilt parts anything is apt to happen.
Cheers
Fred

Is there any possibility that you have air in the system ? Sounds silly but in my car I had to get creative with the location of the radiator and this caused some compromises in routing the hoses. In short, I had to add a couple of hoses to bleed the air in the system.

I attached a pic of the engine room. The top of radiator is just below the water pump pulley and the header tank is on the bulkhead behind the air filter. I had to fabricate an air bleed to the header tank (yellow arrow). The black 1,5" OD steel tube runs from the thermostat housing to the radiator. If that is blocked, my engine overheats within minutes.

There is also another air bleed from the radiator to the header tank.



Hope this is of any help, it is the easiest and cheapest solution to your problem.

Thanks for everyone's inputs. We thought of the water pump / serpentine belt thing, but it turned out not to be the case. The new pump is the same as the old one which was working okay.

I think minorv8's idea of air in the system is actually quite likely. I've seen this on another car. That's what we'll address first when we get the motor put back together!

Thanks again, everyone!