XK140 FHC overheating : water pump ?

This may be a stupid point, but I had a similar problem with my XK-150 and fitted it with a fan kit which came with a thermostat which was to be glued to the
Head somewhere.
I just added a toggle switch under the dash instead, not trusting this approach.
Which it turns out, I haven't had to use (the fan) ever since.
It turned out the problem was oil flow related and upon a simple repair the heating problem went away.
Good Luck in your endeavors.
Pete Pifer
XK-150 OTS
Looking for 1962 Mark 2

Thank you for your help.
George and Otto, I can't use the Otter E-Type thermo switch as it has to be fitted in place of the temp sender already in use. Looking at the url you sent me, I found this switch :
http://www.coolcatcorp.com/Merchant5/merchant.mvc?Screen=PROD&Store_Code...
It's a 16 mm fitting. Do you believe it fit in place of the 5/8" x 18 temp sender without modification on the manifold (I mean re-threading at 16 mm ) ?
Bob, I will try the water pump from m DS420.
I will keep you informed you of the results.
Incidentally, this XK140 FHC is the one figured at : http://www.flickr.com/photos/mrz00p/4910699612/in/photostream
and George contributed 2 years ago to the thread concerning its problems :
http://www.jcna.com/forums/view.php?Vref=JCNA&Vfnum=110&Vthread=5033

Cheers, Yves-Michel CARON

Thank you for your help.
George and Otto, I can't use the Otter E-Type thermo switch as it has to be fitted in place of the temp sender already in use. Looking at the url you sent me, I found this switch :
http://www.coolcatcorp.com/Merchant5/merchant.mvc?Screen=PROD&Store_Code...
It's a 16 mm fitting. Do you believe it fit in place of the 5/8" x 18 temp sender without modification on the manifold (I mean re-threading at 16 mm ) ?
Bob, I will try the water pump from m DS420.
I will keep you informed you of the results.
Incidentally, this XK140 FHC is the one figured at : http://www.flickr.com/photos/mrz00p/4910699612/in/photostream
and George contributed 2 years ago to the thread concerning its problems :
http://www.jcna.com/forums/view.php?Vref=JCNA&Vfnum=110&Vthread=5033

Cheers, Yves-Michel CARON

Yves - you are still using the XK140 water pump which will >not Bob Grossman

Hi Yves,
As George mentioned, it may not be a fan problem but here's the site for the fan switch if you so choose. Click on "cooling system" & it's the 5th item down, FS6, $39.95.

Regards, Otto M.

http://www.coolcatcorp.com/Merchant5/merchant.mvc?Screen=CTGY&Store_Code...

Yves sorry but the direct answer to your question is get an Otter switch for an E-Type. It is the same size but works in reverse--switch closes at about the temp. you requested--same gasket also!

Yves you are still too hot--fitting a elec. fan is treating the symptoms not the issue. I wish I had a better idea but at this point just am stumped--as you. After 20 mins of idle I would expect a good system to show 70-80C at most. Are you absolutely sure the cams are in time? Are you sure the engine is in time? Could you be running lean? I think I would get a laser thermometer and run the car and check for the hot spot--there is at least one!

Yves you are still too hot--fitting a elec. fan is treating the symptoms not the issue. I wish I had a better idea but at this point just am stumped--as you. After 20 mins of idle I would expect a good system to show 70-80C at most. Are you absolutely sure the cams are in time? Are you sure the engine is in time? Could you be running lean? I think I would get a laser thermometer and run the car and check for the hot spot--there is at least one!

Hello everybody who is reading this thread.
The engine i, the gearbox and overdrive have been repaired and are now back in the car;
The overheating problem seems partly solved : I mean that the temp needle doesn't meet anymore the oil pressure gauge needle. After 20 minutes at idle, the temp reach 95?? C. When driving the car even with an outside temp of 35??C, the temp gauge now remains under 90?? C.
In order to obtain this result, I have totally taken apart the engine, cleaned the water galleries, drilled the brass plugs in the head as suggested by Bob, tested the head for cracks.
I still use the water pump who was already fitted (XK 140 type).
I tried to fit the fan from my MKIX (larger diameter than this of XK 140, see attached image) and obtained a better cooling at idle, but as it interferes with the bottom of the fan cowl, I had to refit the original one.
It now sound obviously like an insufficient fan cooling.
I also noticed than the vacuum advance capsule doesn't work very well due to leaks in the caps itself.
The initial ignition timing is adjusted at 5??.
I'm now looking for a thermo switch for triggering the electric fan and I would like to find one than can be fitted in place of the thermo sender in place in the intake manifold (5/8 " x 18 fitting).
Does anyone has an idea of the place where I can find such a thermo switch (ideally 86 ?? C)?
Thank's for any suggestion.

Yves-Michel CARON

George, the head has been tested and is ok.
Bob, the plugs are impossible to unscrew. Sorry.
Does anybody can confirm that these plugs have to be removed (or drilled) when using a SP head with the manifold installed on this engine ? (I have the same manifold installed on my DS420 but I would prefer to avoid taking it apart for verification ...)
Thank's again to all of you for your help.
Yves-Michel

Hello George, I had the same idea and I have already sent the head last week to the workshop for pressure testing. I will let you know the results when I know.
Thank you.
Regards,
Yves-Michel

YVES then my thoughts now are that you have a crack in the internal head casting and since the temp spikes per your description I would pressure test the head. You might be pumping exhaust gas into your cooling system. I have seen that before but it is rare. On the other hand none of our castings are getting younger.

Bob, you are right. The installed pump has a small impeller. I will try with a XJ6 one. About the drilled plug in the by-pass hose, I made this test but it didn't bring any improvement. It was even worse.
Mark, thank you for concern. Just post me your address in case I success in removing the plugs in order to send you these plugs. About the temp sender, as I wrote in my 1st post, I tested with my Mk IX temp gauge (and sender of course as it's a mechanical gauge with capillary).
Regards.
Yves-Michel

If you are going to remove the brass plugs, please try to unscrew them first. Those plugs are almost impossible to find, and I need a set for my spare 3.8l E-type engine, as it had a 4.2l engine intake manifold on it. So save them, and mail them out to me.

Now, reading this thread through, has anyone thought that maybe the temperature sender is faulty? I would have thought that an engine that heated up so much that the temp needle had wrapped around gauge would have shifted a valve guide, or dropped a valve seat with that much heat in the head.

Cheers, Mark R.

Yves- Drilling the brass plugs has worked for me in the past. Of course, the cars were not overheating before the heads were changed from A or B to the straight port configuration. Of greater importance is the kind of water pump you are going to fit to the 4.2L front cover you have pictured. Make sure you are using a 4.2L large impeller pump. This is important.
Also, if you cannot obtain the correct thermostat, you should modify the water by-pass hose by inserting a close fitting wood or aluminum plug that has a 3mm hole in it into the hose about 25mm from the end and clamping it from the outside with a hose clamp.

George, hereunder the picture of the radiator and cap. The radiator neck has an inner diameter of 34 mm and the the manifold neck inner diam. is 30 mm.

Bob, thank you for your help. Do you confirm that I have to drill (or remove if possible) the brass plugs in the head in order to improve the cooling on this configuration?
Right now, the engine is totally dismantled and I will not be able to test before receiving some gearbox parts also needed.

Regards,
Yves-Michel

Yves, two things: The front cover you have in the photo (a 4.2L unit) requires the use of a 4.2L water pump with the larger impeller. The 3.4/3.8L front cover has a finger that separates the pump discharge flow from the suction flow, the 4.2's didn't use this configuration; I drill the brass plugs in the head to 1/2" as you most likely won't be able to remove these plugs without special procedures.
I've used straight port E heads with the two carb manifolds on a number of 3.4/3.8 and 4.0L engines and they work well. I have such an engine in my Mk2 racecar and it doesn't overheat, even in 100F weather.

Hi William,
Thank you for your concern. Yes, I removed the 6 side freeze plugs to check the obstruction of the water galleries. They were clean. I still have to check for the rear one (on the rear side of the block).
Regards,
Yves-Michel

The head serial number matches the block # : R 9036-9

What is the serial number on the head?

George, the radiator is a very recent aluminium one. Seems to be a model designed for XK150 (needs a 2 parts fan shroud). I will post tomorrow a picture of this radiator and the diameter of its neck and of this of the manifold neck.
When I received this car for tuning, it was equipped with many new parts, some of them fitted in a wrong way. For example, the right steering rack mounting was fitted with its front end oriented to the rear ! The damper bolt was totally loosened and the cone was broken in 4 parts. The inlet camshaft was replaced by an exhaust camshaft, the engine core plugs were new but only 'glued' with sealant (they still had their convex shape).
I post hereunder a picture of the engine with the intake manifold removed where we can observe the brass plugs in the head. Do you think they have to be removed on order to match the water galleries in the manifold ?
Regards,
Yves-Michel

Looking at the front cover it is obvious that this engine sat unused for a long period of time. As for the impeller, the critical gap is between the back of the impellor and the Pump body, and it should be as close as possible, no more than 20 thou, But I think the real issue is blocked water galleries, you say they look good but did you remove the freeze plugs to check, you have to, especially the rear ones.

Yves th general condition of your cooling system is poor if the pictures are reflective. The point on the manifold was what angle it is to the neck of the radiator--dismounted it is not possible to tell but the waternecks need to be about equal. In re reading your post I notice you did not mention the condition of the radiator--are you sure it is good?

And the timing cover ...

Hi, George,
Here the pictures of the manifold.
If it can help, the engine is a 3.8 l # R 9036-9 and the timing cover seems from a XJ6 (Leyland logo on it).

Yves send a pictuer of the manifold to radiator neck taken from the side and as near to level as you can!

Oups ! I forgot to put the picture :

Hi, Jag lovers ... and thank you very much for your answers.
Otto, I forgot to mention that the thermostat has also been tested and although it was correctly working, I changed it with a 165?? new one. No improvement. However, I didn't find the correct sleeved thermostat (Bellows ?) which doesn't seem to be available at this time.
George, I'm interested in your suggestion about the manifold. I have seen that the 2 openings in the head matching the 2 holes in the intake manifold (between cylinders 2-3 and 4-5 intakes) are plugged with brass plugs. Maybe these plugs have to be removed ?
Dick, I enclose a picture of the water pump. Left, the water pump of this car and right an old one from my Mk IX. You can see the difference of protruding of the impeller and also the width of its blades aperture.

Just another comment on the water pump. The gap between the impellor and the back of the timing cover is not an issue. The critical dimension is between the impellor blades and the body of the water pump. That is where the water is actually pumped. As your car originally had a 4 blade impellor, if you feel it is a water flow problem, the pump can be rebuilt with a 8 blade impellor. This will flow more water but won't cool it any better. As the cars worked better than this with the stock setup, this is probably not the issue but something to consider if rebuilding the pump. As far as the thermostat, make sure you have the external sleeve style which is correct for this model car.

Just another comment on the water pump. The gap between the impellor and the back of the timing cover is not an issue. The critical dimension is between the impellor blades and the body of the water pump. That is where the water is actually pumped. As your car originally had a 4 blade impellor, if you feel it is a water flow problem, the pump can be rebuilt with a 8 blade impellor. This will flow more water but won't cool it any better. As the cars worked better than this with the stock setup, this is probably not the issue but something to consider if rebuilding the pump. As far as the thermostat, make sure you have the external sleeve style which is correct for this model car.

I am with Otto on this one-although I have seen 140s with changed manifolds go hot because the water neck on the transplanted manifold will not allow flow.

Hi Yves,
You've looked at everything except the thermostat, which, if it doesn't open, will give you this problem. Wait till it's cooled down remove some of the radiator fluid & remove the thermostat. Replace the housing & the water, start the engine & see how far the needle goes. If it stays within the normal range, replace the thermostat with a 165 deg. or whatever Cent. reading comes close to that. The water pump is not always at fault.
If it was a blown head gasket, you would have steam coming out the tailpipe. & water gone from the radiator.

Regards, Otto M.