Vehicles (17 Jan 2019)
You can now add the vehicles you own to your profile as little icons that appear in your profile and alongside your posts.
This is a bit of an experiment. Take a look under the "REWARDS" menu across the top of the screen for the vehicles "ADD/MODIFY" option.
Let me know how you get on.
Engine overheating & losing coolant
I'm hoping one of you experts can help a strictly amateur mechanic to fix his Jimny.
I have a 2003 O2 convertible - for fun, off-road and for my son to use when he is home. It has the G13BB engine - 1298 SOHC. Recently it began to overheat and lose coolant. The radiator was full of mayonnaise. I immediately thought the cylinder head gasket had failed so, rushing in, I took it off. (A lot of cursing and improvising special tools, but ok for a guy who last took a car apart 30 years ago.)
Having finally got to the gasket, I could find no sign of leakage through it. I'm posting some pictures. All comments and advice are welcome.
This is the head as removed, with the gasket still in place. https://ibb.co/eVstT9
This is the head with the gasket off and turned over. https://ibb.co/dSNtT9
This is the top of the block with the head removed. https://ibb.co/nC4MgU
The only clue I could see was one of the cylinder head bolts was heavily coated with a carbon deposit. https://ibb.co/byTggU
Here's a closeup of the corner where the bolt came from. https://ibb.co/jofSMU
Does this mean anything to anyone? All advice gratefully received.
The images are attached in order. I can't find a way to make them appear in the text.
Here you go, for others to see -
This is the head as removed, with the gasket still in place.
This is the head with the gasket off and turned over.(same link as above photo?)
This is the top of the block with the head removed.
The only clue I could see was one of the cylinder head bolts was heavily coated with a carbon deposit.
Here's a closeup of the corner where the bolt came from.
is It Sunday Yet?
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It's not a Jimny. It's my Jimny
Mooo said Ermintrude (black 2011)
Boing said Zebedee (blue automatic2011)
Hello said Florence (silver gv 2.4 2013)
Then you'll know if it was the issue for sure.
The underdog often starts the fight, and occasionally the upper dog deserves to win - Edgar Watson Howe.
My Jimny Thread Here: www.bigjimny.com/index.php/forum?view=topic&catid=8&
To answer the specifics...
Lambert: I see two places that look like combustion gas was escaping, and looking at the gasket I can persuade myself there is a corresponding mark on it. That would explain the carbon deposit on the bolt, but it doesn't show any path for oil to escape into the water jacket. Maybe it's a general indication that the head was not tight at that corner. There is no visible defect after cleaning the head surface.
I didn't think about a compression test. Too late now.
Kirkynut: The head and the block both test flat within tolerance (.1mm) and I'm fighting shy of taking out all the valves and refitting them, so I will refit the head with a new gasket and see what happens.
Mickt: Yep, all the bolts felt the same. They were very tight - tighter than I would expect for a 10mm head, even with 12-point drive. I had to use the torque wrench in reverse to free them. Haven't looked at the specified tightening torque yet.
More generally, looking around, it seems cheaper to buy a whole Jimny same age as mine than have the engine replaced. The risk is I end up with two identical cars,both with clapped engines.
Thanks for the help everyone.
Yes I put it all together by the book - even half tightening the head bolts then releasing them before taking them to full torque. Just like it says in the manual.
When it opens the radiator should heat up evenly across the complete matrix. Cold spots in the direction of flow through the radiator indicate a blockage. Not sure which way the flow is, but assume its hot top to cold bottom. So any difference in temperature between the left and right side must be a blocked channel. Heat should flow evenly down the radiator when the thermostat opens.
Sorry if this has already been suggested.
I am more concerned that there may be a blockage inside the engine itself. It got really gooey when it was spitting oil into the water. I've flushed it out but there are parallel channels where one might be blocked. I dread to think what would happen if one side of the engine was cooled and the other not.
The water pump seems ok - it pumps out water when I disconnect the radiator top hose.