Suzuki Jimny - Water reserve tank boiling over?

[shorn]

Hello all,

Ive been looking for somewhere to ask questions on Jimnys for quite a while so hopefully this is the place!

I have a 2001 1.3 Jimny Soft top, which in January needed the engine replacing. A friend assisted in the engine swap and we successfully (or he mainly did) swapped the engine for a 1.3 from a 2002. (Basically exactly the same)

The car has been running fine, up until recently. The other day after driving for around 30 mins I parked up and noticed water spilling out from under the bonnet and noticed steam aswell. I popped the bonnet and the reserve tank was bubbling up (basically boiling)

Now this has been happening off and on for the past few weeks and some times the reserve tank will be completely empty after driving for a while.

The temp gauge in the car is reading normal and it has not actually overheated at all stopping the car from functioning.

I was hoping that someone might be able to offer any assitance with this, ideas or anything.

The little Jimny has cost a bomb in repairs so far so I want to make sure ive done all I can before handing ot to the garage!!

Thanks in advance!

 

[Softus]

Check the tank cap first.

FYI, a car cooling system at operating temperature exceeds the boiling point of water, so it's pressurised to prevent the water from boiling. The cap is designed to release the pressure if it becomes too great, so a faulty one will leak (and therefore lose) water, sometimes in a dramatic way.

 

[^neo^]

Could be the thermosat sticking, which is cheap and easy to replace.
Also make sure you have the correct mixture of anti-freeze mixed with the water as this also affects the boiling temperature

 

[JohnD]

The thermostat and the pressure cap ae the cheap things. But is the water clean? Are there traces of oil in it? Is there emulsified oil and water in the oil filler cap? You might have a blown head gasket.

 

[shorn]

Thanks for the responses,

The water appears to be clean. The car seems to be varied.

How long should it take for the engine to cool down after driving?
I checked it today about 15 mins after the other half drove home (approx 30 minute motorway drive) and when I turnt teh key the tempterature is still up at the halfway point, and there appears to be no loss of water today.

 

[Softus]

The temp gauge in the car is reading normal and it has not actually overheated at all stopping the car from functioning.

Could be the thermosat sticking

 

[davieboy]

you say the engine was replaced? can i ask what was wrong with the original??

 

[johnb80]

You can rule out sticking thermostat because the temp shows normal when driving around.

The most likely cause is loss of pressure and the most likely culprit is the expansion tank cap. Go to halfrauds and get a new one.

Regards - JB

 

[shorn]

OK,

Spoke to Suzuki, who seemed to think it sounded like the head gasket had blown, so I have now replaced the head gasket.
In the process I removed the thermostat as I tested it and it didnt seem to be opening until it the water was boiling.
Took it for a motorway spin after chnaging the head gasket, all seemed fine. Drove for a bit longer and checked it when I got home, and it seemed as though boiling water was being forced into the reserve tank still, and water was definatley boiling in the top radiator hose, so I am baffled. Next thing im going to remove/inspect/test is the water pump.

If anyone has anymore ideas Id be glad to hear them.

 

[Softus]

Have. You. Checked. The. Tank. Cap.

 

[johnb80]

RADIATOR CAP as suggested earlier. In one way I hope it isn't this because you'll be kicking yourself if this is the cause. On the other hand I'd be able to say I told you so

Engines run around boiling point, without the pressure the water will boil. Raise the pressure and water will not boil at 100 deg C. So all of this fits the symptoms.

Regards - JB

 

[Softus]

RADIATOR CAP

Not raditator cap, but tank cap.

...I'd be able to say I told you so

If you're actually capable of being that mean, then perhaps you should first consider that you didn't actually tell him, you simply repeated the solution that I'd already suggested, and gave an explanation that I'd already given.

 

[johnb80]

Softus, I humbly apologise, I hadn't noted your earlier comments..... must have been one of my 'senior' moments

I'm really suprised that this hasn't been tried first and I feel gutted for shorn if he's incurred all this work/expence for such a simple item.

A few years ago I bought a 24v Senator with £2,000 knocked off because of a blown head gasket, when I got it home the engine was sweet, no steam from the exhaust and it only boiled after a drive. Replacing the expansion tank cap solved the problem total cost £5.50

Regards - J

 

[Softus]

Thanks for that johnb80.

I'd also be gutted, but it's odd how some people post a question here and give the impression of not reading the answers.

 

[JohnD]

I like to post an answer without reading the question