Hi,My Jimny has some issues that may or may not be related.In summary:
Symptoms: The Engine misfires. Overheats in traffic. Leaky core plug.
Parts replaced: Thermostat, Radiator and cap, water pump, fan coupling.The full sorry tale:
About a year ago, it started pushing coolant into the expansion tank but not returning it to the radiator when cooling down. So the expansion tank would fill over a few days and the radiator would empty at about 100ml (half a coffee mug) every other day.
At about the same time I noticed a leaky core plug so I replaced it.
The problem persisted so one-at-a-time I replaced the radiator and cap, thermostat and water pump. The thermostat and radiator cap were genuine from the Dealer as I know they can be a bit problematic.
The car was being used everyday and the coolant closely monitored and ran flawlessly.
It ran hot once when I forgot to top up the coolant but the needle never got to the top and no warning light came on.
The oil is not milky at all, and the car has never overheated to my knowledge.Inside the cab, the heater doesn’t work very well at all and the fan, although it roars away like a trooper, produces very little wind. The result is a Luke warm breeze that isn’t enough to clear the screen. The cable on the side of the console appears to slide fine but I can’t get any decent wind out of any vents at all. I’ve has to buy a 12V heater fan from Amazin to clear the screen.Recently the car developed a misfire when cold.
I ‘contact cleaned’ the plugs to the coil packs and the two connectors on the left of the rocker cover.
No difference.While rooting around for the cause of the misfire, I found the fan coupling to be bad, so I replaced it.
I also spotted another leaky core plug.I cleaned and re-gapped the spark plugs which made, which made no difference.
I’m not a mechanic but various forums say it could be the head gasket. My logic says that if it is the head gasket, using Steel Seal may solve the problem and if so, I’ll definitely know it needs to be replaced.The Steel Seal company say that Ethyl Glycol coolant must be used so I flushed the old pink stuff out completely, which took about 30 litres of distilled water (not cheap !). This was done by draining the radiator, topping up with water and driving round the block to get the thermostat open again, then redraining. While draining I noticed while the top hose got hot, the water at the bottom of the rad was cool to the touch. And heated gradually as it drained over my hand, but was never hot enough to be uncomfortable. Each drawining gave me about 3.5-4 litres from the radiator.
Once the contents of the cooling system were 95% clear, the Steel Seal was added to the radiator, followed by the 50/50 blue Ethyl Glycol coolant and distilled water mix.
Following the instructions on the Steel Seal bottle, I ran the engine up to temperature and left it idling for 30 minutes.
When I returned to the vehicle after 30 minutes, the temperature gauge was at MAX so I shut the engine off and went to cry in the corner.
The morning after, I decided to drive the car around a bit to see how it behaved.
I checked the coolant level and added about 100ml. My drive angles up at about 5 degrees so the Radiator cap was the highest point. In theory no airlock issue.
It now runs like the thermostat is goosed; temperature climbs in stop/start traffic, so is now parked up !
This morning I started it up and heard a faint clattering from the front cylinder (I think). Almost like you’d hear from a diesel engine. The misfire was still present. The car was shut off after about 30 seconds.And that was that !
The fact that the pink coolant was being pushed to the radiator indicates that the thermostat is working, although I could be wrong.
My next check is to see if there’s blue coolant in the heater core, but after that, I’m stumped.Whew !If anyone has any advice, I’d greatly appreciate your input.
Otherwise I’ll have to explain this to a mechanic and bend over to pay the bill.
