V50 General : What could it be??

[TallPaul1975]

So been having issues with our 2010 1.6D Volvo V50 more or less since we got it around 2 years ago,as it would over heat usually when on motorway at speed, high temperature engine warning light would come on had lots of things changed on it, such as new thermostat, new temp sensor, coolant system drained and flushed, new EGR, new EGR cooler.

We were getting alot of pressure in the coolant system, had a sniff test done which came back all ok, on bypassing the EGR cooler it seemed to solve the problem. So hence why we got a new egr cooler. Been having issues with the DPF getting completely full, message on vida dice saying, DPF overcharged not possible to do regeneration. Turns out the Eolys additive tank was empty, so ordered some JLM fluid and topped it up, reset the counter via the DICE.

Got a K2 DPF cleaning kit which included the aerosol spray which you spray directly into the DPF via removing the pressure sensor and inserting nozzle, also a concentrated bottle to add to the fuel.

Well after doing the clean, it reduced the reading low enough to be able to intiated a forced regeneration with my Vida, done it twice and then took it for a nice long run on the motorway. HOWEVER here is where the problems start, it was running really lovely, loads of power, temperture stayed bang on half way for about 10 mins then started to rise, but as quick as it started to rise, as soon as I backed off the gas a bit it dropped quickly back to half way. Done this a further 2 times whilst driving along. I tried putting the heating on hot and fans on to see if it made any difference and it seemed to lower the temp very quickly.

What could be causing this, By way of thinking, I'm ruling out thermostat as it wouldn't be just for a few seconds then ok again, same with the water pump, it would be a constant problem, don't think it would be the radiator blocked or anything.

So thinking either, faulty sensor or air lock? But really not sure to be honest, so any ideas, comments or advice would be very welcome.

We are just really fed up with the constant issues with this car. We took it to a mechanic who told us it was the water pump and quoted us £400 to change it along with the cam belt. When we phoned volvo they told us that it's very rare for the water pumps to need changing on these vehicles and they usually last the lifetime of the vehicle, and cam belts are done at 90000 miles, our car as only got 75000 miles on the clock.

[TallPaul1975]

Very surprised to see the amount of people who have viewed this post but no one as replied. Would have thought with all the clever people in this forum I would have had at least one reply.

[Welton]

Proper Volvo water pumps are tough, they have a Brass impeller and don't fail, I wonder if the 2.0D (with its PSA backgound) has a plastic pump impeller? I don't know but could be checking - some plastic pumps can shear off and stop circulating the water.

Other possibilities are that in the past someone has added a bottle of 'stop leak' or something in the system and that stuff CAN block the radiator - only way to tell is either by infra-red thermometer checking for hot and cold areas with the engine at running temp OR remove the rad and back-flush it to see what comes out.

I hope this helps but I can't give you a definite answer, these are just the things that sprang into mind.

[TallPaul1975]

Originally Posted by Welton

Proper Volvo water pumps are tough, they have a Brass impeller and don't fail, I wonder if the 2.0D (with its PSA backgound) has a plastic pump impeller? I don't know but could be checking - some plastic pumps can shear off and stop circulating the water.

Other possibilities are that in the past someone has added a bottle of 'stop leak' or something in the system and that stuff CAN block the radiator - only way to tell is either by infra-red thermometer checking for hot and cold areas with the engine at running temp OR remove the rad and back-flush it to see what comes out.

I hope this helps but I can't give you a definite answer, these are just the things that sprang into mind.

Thanks for your advice Welton, mine is the 1.6D not the 2.0D, and would have thought that if the water pump was at fault it would be a more permanent issue just not a quick intermittent issue. Sometimes as quick as it goes up it drops back down again.

Also last year I completely drained the coolant system and flushed through with a hose until it was running clear, then refilled with fresh coolant. The thermostat and temp sensor have both been replaced.

I'm stumped, baffled by this on going issue. Think it's time to take it either to a garage who knows what they are doing or Volvo.

[MDS40]

" Sometimes as quick as it goes up it drops back down again."

In that case i doubt the coolant itself has overheated as it takes a while to cool off.

[MDS40]

I don't know too much about these engines but some cars now have two sensors for this, one for the coolant temp and one for the cylinder head temp.

[TallPaul1975]

So just a quick update to our ongoing problem we've been havin gwith our 2010 1.6D V50. After spending a fair bit of money on it, mainly parts £600, finally sorted the intermittent over heating issue out.

I bought a replacement INA water pump timing belt kit from SC Motors and with the help of a mechanic friend we removed the water pump to replace and straight away it was obvious that this was the fault, firstly the belt and the water pump looked recently changed, Continental timing belt new idlers but water pump had so much silicone around it and holding it in, on removing it, holding onto the teethed gog side tight, I was then able to spin the pump side freely. So probably at low speed the pump was sort of working, but once the water temperature rises and speed increases, the pump was probably just slipping.

Also examining the old water pump, the impeller was plastic, and there was no markings on it, no numbers, no brand name etc. Looked like a cheapo one, with paper gasket which had completely disintegrated hence the need for all the silcone I expect.

Anyway the one we put on was also a plastic impeller but at least had a metal gasket.

New belt, new tensioner and idler, new water pump all fitted, new coolant, all bled properly and no further issues. We are currently in Poland and we drove the 1033km distance with no issues at all, averaging around 57mpg at around 80-85 mph. Tyre pressure was very low as well didn't realise but when we arrived and checked all 4 tyres were showing 26 psi. Since inflating to correct PSI we have seen even a better return on the mpg.

Job done only took around 3hrs to do the work, LHS engine mount did have to come off and engine/gearbox supported.

[rowdy]

Glad it's sorted, but the dpf issue may come back sooner rather than later, as I think they are supposed to be replaced at around 75k

[iainmd]

Agree. Never convinced that cleaning isn't a false dawn. Would recommend replacement at the service interval of 75k to avoid problems, speaking from experience.