Cooling problem

[philmas]

Hello!
I recently had the following issue: The big hose in the front of the engine (running from the radiator to the thermostat) suddenly blew up , and I lost a large amount of the coolant.
I stopped the engine immediately when I saw steam coming out.
I managed to get someone repair the hose on the go, and filled the expansion tank.
But I noticed that the engine runs very rough at low revs, and cannot handle a correct idle any more when hot, as everythig looks normal when the engine is cold ( starting, idle, OK).
Oil check is OK, no obvious  coolant leak  (for what I can see...) , water temperature OK...
What do you think?
Could it be a leaking head gasket, or worse, symptoms of a warped head leading to an air leak...? Thank you for help!

[Leester]

Hello Phillipe, it sounds like coolant has gone everywhere in the engine bay. I would try drying out everything as much as possible, especially anything to do with the ignition system. Pull spark plug wires one at a time, dry them off, dry off the spark plug area, reattach plug wire and go on to the next plug. Look over all the ignition wiring plus any wiring to the injection pump and dry as needed. Dry off around the distributor cap, maybe pull the cap and see if there's any moisture inside the cap or in the distributor. Good luck, Lee

[WRe]

Hi,
I would suspect a blown cylinder head gasket. Take a look at the inside of the  the oil filler cap, whether you can see any oil-water mixture there, looks like creamy butter. You/your workshop could also do a pressure test of the cooling system.
https://youtu.be/5zpNjYmmiYY
...WRe

[Mike Hughes]

Is there an air pocket bleeding procedure when refilling the coolant system on a 113?

[philmas]

Thanks for these precious infos.
I was indeed suspecting an ignition issue as coolant has spread everywhere, and especially on the distributor and plug wires, but it is dry by now and left white marks all around the engine bay..
What is challenging is that everything is normal when cold.
When engine is warm, it is just impossible to drive the car under 2000 revs, and it won't hold idle.
I'll remove the oil filler cap, looking for "mayonnaise" (OMG )...

[Harry]

What was the operating condition of the engine before the incident?  If you didn't allow it to get overheated, there's no reason to think the head gasket is blown or the head is warped.  How did the hose look before it blew?  Was it old?  Does it look like a bubble (or weak spot) had formed, then it ruptured?  Normally, that's what you see when a hose fails.  I suspect it would take a lot of pressure to reach a point where a good hose would simply fail.

[philmas]

I suspect the hose was pretty old, like the other ones ...I know I should have changed them all preventively ( )!
I really don't know how it happend: car was running great, but I confess it has never been perfect at low revs when warm in 20years... water temperature was ok, as usual,  then suddenly the car began to miss and hesitate, and there was steam coming out of the engine bay two minutes afterwards!
The hose had cracked under the proximal collar near the thermostat housing, but it was not properly "blown out".
Anyway, the leak was obvious on inspection, there was coolant all over the place but nothing  left in the expansion tank.
Is the dashboard thermometer reliable? It never indicated overheating.

[Leester]

Agree with all comments but before you pull the head suggest you follow Mike Hughes suggestion and see if you have an air pocket.  Also, I don't know how much they cost today but compression testers used to be cheap and easy to use. With respect to your dashboard temperature sensor - if it was working properly before the blow, there really shouldn't be any reason why its not reading correctly now. You can always remove it (carefully - don't bend the capillary tube any more than necessary) from the pod and dip it in water of known temperature to test.

[Todd]

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[Harry]

Agree on the compression test.  Removing the head is a big step.  I wouldn't go down that path unless I was very sure that was the problem. The place where your hose failed (near the clamp and radiator nozzle) is not atypical.

[philmas]

Thanks to you all.
I'll start with pulling spark pugs and oil filler cap first,  then perform a pressure/ compression  test and  we'll see...!
Just in case...can a wraped head be saved or...?

[Todd]

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[philmas]

That makes sense …
Running when cold is perfect, idle is just fine, water temp stable at 80-90°C. Doesn’t that mean the WRD, hence the thermostat, is operating fine?
When really warm (after 30-45min), the engine runs very bad at low revs and stalls, but looks ok above 2000 revs and the temp is still OK.
 Could I try a test of the WRD by removing the small air filter, and see if there is still a dépression when engine is hot …?
Maybe one of the best clues of an internal leak would be water consumption, don’t you think ?
What should be the max and min coolant level in the tank?

A stupid question:
Where can I find the correct plug wire order? I have disconnected/reconnected all the wires from the distributor, and I was confident with the result, but you made me doubt …!
Thanks again for your help !

[philmas]

Ok,lots of questions, sorry for that…
Anyway, part of my question was actually stupid: firing order is engraved on the head cover 
There is a « 1 » on the distributor cap, so I assume one  should just follow the firing order and plug in the wires clockwise…!
The engine would probably run poorly even  when cold if wires were swapped…

[Todd]

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[lurtch]

Hello philmas,

     Here is a photo of what was causing my "cooling problems".

Larry in CA

 

[Todd]

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[philmas]

I started my inspection yesterday night.
It proved to be very instructive : no mayonnaise on the oil filler cap; no evidence  of leak around the head gasket, at least with cold engine.
I inspected the spart plugs wires : firing order was OK….
But there was a surprise by opening of the distributor cap: the rotor’s end was completely blown, and the copper contact was gone !
I don’t understand how the engine could possibly even start under such conditions…
SO, further investigation will follow as soon as I receive a new rotor!
Anyway, I find the whole story to be challenging: how could the cooling issue be related to the ignition failure …

[Todd]

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[philmas]

I already ordered a new cap and rotor from SLS…not sure they are BOSCH though
Do you think that some ignition related malfunction are likely to occur or  get worse with hot engine (electric arcing, weak spark and irregular flame front…)?
Anyway, inspection tour, part II, is starting today: pulling spark plugs, checking hoses (I bought the whole replacement set…), waiting for the new ignition parts…

[450sl]

Philmas , Have you checked your viscocluth is working ok ?

[Todd]

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[philmas]

How do you test the visco-clutch ?

[Todd]

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