overheating problem

After 10 months of care free driving, apart from my hit and miss first gear problem, ( less problematic now as I've developed a technique ), the jimny, (2005 vvt) overheated on the motorway, I pulled over to find the expansion tank full and boiling over. I let the engine cool down, topped up the rad from the ET and added more coolant so the levels were right and continued the journey, temp gauge at normal for around 30 min then went from normal to full red in around 5 seconds. Pulled over, again boiling full ET, Drove the rest of the way home by driving for 20 min then stopping for same to let the engine cool, so didn't go into the red again.

Next day after some research changed the thermostat and rad cap, flushed the system and added new coolant drove around town for a few days without a problem, back on the motorway, same thing happened again. This time when I saw the temp gauge start to move I put the heater on full, this actually made the temp go up even quicker, revving the engine made the temp go down. I drove down the hard shoulder a bit in second at high revs the temp went to normal, I continued for another 30 min, overheated, this time revving didn't work and had to do the coolant from ET to rad procedure and again limp home.

I now go back to the day I bought the jimny, I drove it from Derby to London, next day it overheated, I checked the rad and topped it up, it took 2 litres of coolant, I talked to the guy who sold it, asked if he knew why the cooling system was short by 2 litres, he said he hadn't checked for a while, if I knew then what I know now I would have had a lot more questions. Anyhow the jimny was fine then, a couple of months later I checked the coolant and it needed topping up again, around 1 liter, then good till the motorway experience 6 months later

I did a chemical test for exhaust gases in the rad and the colour change indicated there were exhaust fumes in the coolant. There's no sign of water in oil or oil in water, no visible exhaust gasses. Engine has loads of power and runs very smooth. I used a gasket seal product in the coolant, again driving around town no problems, after 120 miles of motorway driving same problem again.

No visible signs of leaks, the fan seems fine, is stiff when cold, the radiator gets hot evenly. I am a bit suspicious of the fan as I never hear it kick in, it's on as soon as I start the engine and remains on. There is good internal heating.

I'm thinking there has been a slight leak somewhere in the water jacket since I bought it and it gradually got worse, or there is now a secondary problem, btw once the coolant is in the ET it doesn't go back to the rad. One last thing which is a bit odd, a mechanic who was having a look noticed a cable tie wrapped around one of the hoses leading to the heater at the back of the engine, there seemed no reason for it and it was actually making a kink in the pipe restricting flow, he said it could have been an attempt at sabotage by a dodgy mechanic and took it off.

So my choice is start replacing everything starting with the fan clutch, water pump, rad etc possibly to finally accept its a head gasket problem.
Or change the engine, and may as well the gearbox at the same time so I can have a reliable 1st gear again, Does anyone have any ideas re what to try to further diagnose the overheating problem ? Or, just as welcome, does anyone know of a good place to take the jimny for an engine / gearbox replacement and roughly at what cost, thanks for any help or suggestions

If the test you did showed exhaust gases in the coolant, then its a head skim and new gasket needed, the rest of it sounds fine.

If your going to the trouble of swapping the engine, then its an ideal opportunity to go to the 1.6

Hi Riccy. Is that the vitara engine? Is there a lot of moding to do or does it fit as is and compatible with existing running gear? Do you know anywhere that is good for this kind of work?

Its in a few different suzuki's incl vitara, sx4, swift sport and liana i think.

Basically, match vvt to vvt (or not as the case might be). You have a vvt so try and get a vvt motor from a 2006-2010 car. The engine code you want is 'M16a VVT'. The VVT has a bulge on the front (or side if in a 2wd car).

Mine came from a 2010 swift sport that had been rear ended at 40k. After that year there is some messing about with the vvt trigger wheel needed i think (crank out job:-( ). Search on bigjimny about swift sport into a vvt jimny, theres loads of info.

Regarding who to do it, i couldn't say. I did mine myself, but i am blessed with a basic mechanical knowledge and basic tools & workshop space. its not difficult, but you do need time, space and patience!
A garage would probably charge a fair bit as theres not set 'guide' for each donor motor and end preferences. Various parts need to be transplanted and most garages employ 'parts fitters' in many cases, so some research would be needed.

thanks for that definitely something to consider. I used to do work on my cars but now no tools, no space, little time. I'd like to just drop it off somewhere and pick it up a week later all done.
What would I expect to pay to have the head skimmed and new gasket fitted? Anyone had this done?

Definitely head gasket if there are combustion fumes in the coolant. Get a new water pump fitted too. I would have thought it would be about £500 from a local garage.

kirkynut wrote: I think it might be the viscous fan not locking up when hot.

Unfortunately by repeatedly overheating it, you may have blown the head gasket.

Kirkynut

I suspect that's exactly what happened, though the last 4 days driving around London everything seems normal again, no overheating and now the coolant is returning to the radiator and the level in the rad is where it should be, it's hard to believe there's such a serious problem when all feels normal. I'll do another chemical test and see if anything changed. Maybe the sealant actually worked and now I'm back with the original problem of overheating just on the motorway

Busta wrote: Definitely head gasket if there are combustion fumes in the coolant. Get a new water pump fitted too. I would have thought it would be about £500 from a local garage.

Thanks. My best price so far is 450 including skimming, how likely is it a cracked block? If so would I be seeing other symptoms?
Or would they be the same as a damaged head gasket?

Very unlikely to be a cracked block. I've never heard of one cracking.