[Jim R]

Hi. Travelling uphill, my 2.9 diesel looses acceleration/power for about a minute, coupled with an instant rise in temperature. It then starts to accelerate again and temp goes back down. Latest sign sounds like steam escaping. Mentioned it to a number of garages and no one has a clue. Grateful for any help as I'm having to use the car to travel on a long journey every week. Thanks. Jim

 

[f0ster]

sounds like it might be overheating, rad might be getting blocked internally or even externally, you might try a thermostat.

 

[Jim R]

sounds like it might be overheating, rad might be getting blocked internally or even externally, you might try a thermostat.

Thanks f0ster. I had thought about that but there's a definite correlational between the loss of acceleration and temperature rise when going up hill. Could that really be a a thermostat?

 

[NUFCblake]

Flush your cooling system. Change your thermostat and your system caps.

If your overheating under load then your radiator may not be getting the flow it needs which if to hot can trigger a limp mode.

Also your coolant isn't linked to the expansion tank. It's just an over flow. And it doesn't return. Check with the cap on the housing your coolant should be visible.

 

[NUFCblake]

Also check your air filter and get some maf cleaner

 

[SiW]

Sounds like a possible air lock in the cooling system.
is the expansion tank pressurised when this happens?

 

[f0ster]

the temp rise is the ecu safety circuit cutting in, if it detects overheat it limits the power to try and protect itself and to let the driver know,

 

[Jim R]

So it looks like you're all pointing in the same direction. I'll give it a go in the next couple of days and report back. Thanks very much for your replies.

 

[Crickleymal]

It's the instant rise in temperature that intrigues me. Could it be a loose wire to the temperature sensor that is shorting out going uphill making the ECU think it's over temp and then triggering the power [email protected]

 

[Jim R]

It's the instant rise in temperature that intrigues me. Could it be a loose wire to the temperature sensor that is shorting out going uphill making the ECU think it's over temp and then triggering the power [email protected]

Yes it's weird Malc. I've had the loss of power thing for about three weeks but after a week noticed that every time it happened, the temperature went up at the same time. It happens on long and short journeys. I'm driving from Surrey to Devon every other week and I now know exactly which hill it's going to happen on! The other guys have made some good suggestions, so I'll start there but everything is worth considering.

 

[Jim R]

So I managed this week to drain the rad, change thermostat (the old one was ok though) and change the cap, which had a rubber that looked perished. Then refilled it with 7 litres of mixed coolant (even though it says the systems takes 11 litres) . Had to go to Worthing today from Kingston and it didn't falter once, so fingers crossed, it's worked! Thanks for all your ideas people.

 

[Jim R]

So I managed this week to drain the rad, change thermostat (the old one was ok though) and change the cap, which had a rubber that looked perished. Then refilled it with 7 litres of mixed coolant (even though it says the systems takes 11 litres) . Had to go to Worthing today from Kingston and it didn't falter once, so fingers crossed, it's worked! Thanks for all your ideas people.

PS and the warning lights gone out on it's own.

 

[maxaret]

Will keep fingers crossed for you Jim.
Don't forget to keep an eye on the coolant level in case of any air working its way out of the system.
The 7 litre refill might be because of some airlocks and/or because the heater system retained some coolant perhaps.

 

[Jim R]

Ok first of all a big thanks to you for your suggestions, which were spot on so I though I'd tell you exactly what I did. Changed the coolant, the thermostat (which was fine) and the cap. When I removed the cap the second time I noticed that the rubber washer was partly stuck to the rim and looking at it closely you could see some deep channeling on it. I think because of this it was loosing coolant and as you say, triggering the ecu to go into a semi limp mode when going up hill. On the way down hill, the coolant that was left, was cooling the engine. I've now been on a couple of long trips so the issue looks fixed. Thanks again everyone. Jim

 

[Jim R]

Sorry to burden everyone with this again but the problem has now changed slightly. The engine light doesn't come on, the temp gauge stays at normal but at the first sign of a hill, the acceleration just drops. On the flat it runs along at 80 but there is no instant pull when I hit the accelerator. Anymore ideas?

 

[maxaret]

Hi Jim
I would probably suggest some basic checks/work
Replace Air Filter if required and maybe put some good quality Fuel System cleaner in the tank (Millers/Forte etc).
When was the Fuel Filter last changed ?
Check for any binding brakes.
Does it go better with A/C switched 'on' ? (EGR related)
Other possibilities might be problems with Turbo not spooling up (turbo control/operating system) or leaking turbo pipery/vacuum pipes and/or clogged/damaged intercooler and associated pipery.

 

[Jim R]

Hi Jim
I would probably suggest some basic checks/work
Replace Air Filter if required and maybe put some good quality Fuel System cleaner in the tank (Millers/Forte etc).
When was the Fuel Filter last changed ?
Check for any binding brakes.
Does it go better with A/C switched 'on' ? (EGR related)
Other possibilities might be problems with Turbo not spooling up (turbo control/operating system) or leaking turbo pipery/vacuum pipes and/or clogged/damaged intercooler and associated pipery.

Thanks Maxaret. I've been using millers oils in the fuel. Not sure about the filter but was thinking about changing it. It's not a brake thing, it's a definite drop in acceleration. It just falls away and I have to get in the slow lane. Air con is down at present. I think there's a leak as I keep seeing water at the back, offside end. Turbos I have no experience with. Anyone know a good mechanic near Kingston?!!!

 

[maxaret]

Hi Jim
Our A/C does not work either but I keep it switched on as it probably disables the EGR circuit,I only mentioned A/C as a possible diagnostic help.
If you have a leak visible you would be using a fair bit of coolant.

 

[Jim R]

Hi Jim
Our A/C does not work either but I keep it switched on as it probably disables the EGR circuit,I only mentioned A/C as a possible diagnostic help.
If you have a leak visible you would be using a fair bit of coolant.

Cooling is currently by operating an electric motor to displace a sheet of glass!

 

[Jim R]

Right here's a follow up in case it helps anyone. Spent two days trying to sort this. Kia said "four weeks" and no one locally wanted to get involved so local friendly garage ran another test (even though there was no engine light on) and found error 2015. I'd seen it before but it didn't make any sense bearing in mind what was happening. It's a fault with the inlet flaps and basically interferes with the inlet manifolds job. I'd previously checked the motor at the end and it seemed to be working but I checked again and noticed that the rod from the motor to the flaps was not opening as far as it should. Once disconnected, the motor was ok so I stripped down the connecting rod, wd 40'd it for most of the day, separated it and cleaned it with wire wool and then re-greased both ends of the rod. It now runs much better on the flat but of course I have to find a hill to be sure (better get back to Devon then!) So the thing about going up hill was basically that the engine wasn't getting enough fuel. Thanks to everyone for your thoughts. Hope this helps someone else. Jim