Coolant loss v70 t5 1999

[850timj]

Well my trusty 196,000 T5 has developed a thirst for coolant. It uses a header tank full in about 150 miles - a little variable. There are no visible external leaks, no sludge in oil or signs of leaky heater matrix. Rad probably 5-6 years old IRC. So i'm wondering about head gasket or cracked liner?
Is occasionally a bit of a stutter on start up. I took the plugs out and No 1 cylinder looks very clean when eyeballing down the plug hole - can read the letters on the piston - the others look more carbon coated.
Have just ordered block combustion tester kit but any thoughts? I was under the impression that HGF extremely rare and cracked liners were more 2.5 V70R and Ford territory?

[Alpine]

leaking heater matrix? Check if the front footwell carpets are damp.

[Baffler]

Indeed HG failure is relatively rare. Are you seeing excessive water vapour from the rear end?

Check the lower hose from the expansion tank to metal pipe at the rear of the engine. If the clip is loose or the hose has swelled it can allow coolant to seep past and burn off on the hot exhaust. If there is a deposit of fur on the metal pipe clean it off before refitting the hose.

[214299]

I have a little experience in chasing Volvo coolant loss on my 1998 S70 Is the management light on?

Loose hose clip
Failing hose
Pin prick hole in expansion tank underneath that you can’t see
Faulty expansion tank cap
Small leak on thermostat housing M7 thread Torx screws
Faulty engine coolant sensor by thermostat housing
Faulty O ring on radiator drain plug
Faulty front coolant sensor
Pin hole(s) in radiator
Does the jiggle pin on the thermostat face the housing hole nearest the bulkhead to allow the system to be bled properly to get all the air out



Only use a Volvo OEM thermostat some aftermarket stats are slightly too large and get crushed on top slightly when tightening the housing hence not sealing correctly.

Heater matrix

Buy a head gasket testing kit from Ebay cheap enough and see if there are any gases in the coolant indicating blown head gasket.

Last but not least the 2 heater pipes going through the bulkhead into the cabin have O rings on them and are a common age failure. Are the carpets wet?

[214299]

was a dodgy Camshaft Position Sensor wire, at first I thought it was fuel related.

Apparently these sensors can be a common problem. They are cheap but a pain to fit.

There is a spring clip on the old sensor that needs to go onto the new one.

[850timj]

Originally Posted by Alpine

leaking heater matrix? Check if the front footwell carpets are damp.

Sadly carpets are dry....

[850timj]

Originally Posted by Baffler

Indeed HG failure is relatively rare. Are you seeing excessive water vapour from the rear end?

No. That is the slightly puzzling thing as now going from full to level warning light in 10-12 miles!! All that water must be going somewhere and its not obvious externally....

Check the lower hose from the expansion tank to metal pipe at the rear of the engine. If the clip is loose or the hose has swelled it can allow coolant to seep past and burn off on the hot exhaust. If there is a deposit of fur on the metal pipe clean it off before refitting the hose.

I did wonder about this as there is some furring on that connection. Also perhaps coincidental but after inspecting the piston tops, I had tried tightening the various hose clips and then usage has increased - but still nothing obviously visible.

Will try the combustion gas test and report back.

[Keith M]

I recently had a very similar set of circumstances with my 2003 C70 2.0 at 186000miles.
It had started using coolant at about a rate of 1 litre every 200 miles or so getting slowly worse.
After searching a lot of the chats hear checked out pipework around turbo etc - all looking good. Could never find any coolant under car or signs in the oil.
When I took it in for its MOT, I asked the lad who did it if he would have a close look around for me. He thought there were indications around the water pump
I had the cambelt replaced by Volvo about 15,000 miles ago and they recommended not replacing the water pump at the time. (Hindsight wonderful).
Volvo recommended replacing pump without changing cambelt again, which I did this time as I had a bit more time on my hands (and less money )
I thought there seemed a little play in the old pump and wasn't completely convinced but a recent trip to Cornwall and back during the recent heatwave and all is good. No loss at all.
Happy days

[850timj]

Its a thought. I changed the waterpump with genuine volvo part 6-7 years ago, and did wonder if that would last as long as the original. I changed the cambelt early last year as had to do cam seals and no sign of leaking then. It is on my list to pull the cover off and have a look but have discovered damp carpet this morning, suggesting heater matrix is at least contributing.

Originally Posted by Keith M

I recently had a very similar set of circumstances with my 2003 C70 2.0 at 186000miles.
It had started using coolant at about a rate of 1 litre every 200 miles or so getting slowly worse.
After searching a lot of the chats hear checked out pipework around turbo etc - all looking good. Could never find any coolant under car or signs in the oil.
When I took it in for its MOT, I asked the lad who did it if he would have a close look around for me. He thought there were indications around the water pump
I had the cambelt replaced by Volvo about 15,000 miles ago and they recommended not replacing the water pump at the time. (Hindsight wonderful).
Volvo recommended replacing pump without changing cambelt again, which I did this time as I had a bit more time on my hands (and less money )
I thought there seemed a little play in the old pump and wasn't completely convinced but a recent trip to Cornwall and back during the recent heatwave and all is good. No loss at all.
Happy days

[850timj]

Quick update, as I know how annoying it is when people don't post what the issues and fixes turned out to be!
Combustion gas test proved negative. Water level a bit chaotic during that (?) and did witness some slight steam from exhaust but that was just after warming up, so guess could be normal exhaust condensation. Re-checked under passenger floor mat and is definitely wet in there. Surprises me it wasn't completely awash as had put another 0.5 litre of water in only to see the level drop again! So next step is have ordered up new matrix to fit at the weekend.