Coolant leak front centre of car

[360beast]

Originally Posted by kiloran

No overheating as far as I'm aware. No steam out of the back, no obvious mixing of oil and coolant, clean coolant dripping out, temp gauge has never gone above midway. It's gone at the driver's side front corner of the head above the water pump.

That's not sounding like the head gasket then, that sounds just like the waterpump top seal.

[kiloran]

Originally Posted by 360beast

That's not sounding like the head gasket then, that sounds just like the waterpump top seal.

Definitely HG - it's coming from the head in a line just aft of the manifold stud in the picture, dripping almost directly on to the sensor below it. When I burped the water pump hose by hand I could see it dribble out.

PXL_20210707_175734675 copy.jpg

[360beast]

Originally Posted by kiloran

Definitely HG - it's coming from the head in a line just aft of the manifold stud in the picture, dripping almost directly on to the sensor below it. When I burped the water pump hose by hand I could see it dribble out.

Attachment 136288

Sir your head gasket has blown! When you said above the waterpump the only thing above it is the top seal which threw me.

Yes you can skim the head, Dave has just looked it up for me on his Volvo data pocket.

New height of head 146.1mm
Min height after machining 145.6.mm

Max warp along head 0.5mm
Max warp across 0.25mm

In Sweden and America I have heard of people over skimming heads to increase compression for N/A builds.

I've just had my head skimmed before fitting a 531 head, absolutely no issues with the timing marks or anything. A customer of mine bought a B200F off of me for his boat, he messaged me a few months later complaining the head gasket had blown after fitting a new one. It was absolutely fine running in the car, long story short he didn't get the head skimmed so it blew the head gasket straight away, he took it off and got it skimmed and another set of bolts and it was fine.

So yes, make sure you get the head skimmed.

[Clan]

Originally Posted by kiloran

No overheating as far as I'm aware. No steam out of the back, no obvious mixing of oil and coolant, clean coolant dripping out, temp gauge has never gone above midway. It's gone at the driver's side front corner of the head above the water pump.

firstly sorry about the no skimming , I was thinking Diesel for some reason !

I suspect corrosion rather than a blow if you haven't overheated it .
What had been the state of the coolant over the years ? This will have been a long term thing over many years ...

[360beast]

Originally Posted by Clan

firstly sorry about the no skimming , I was thinking Diesel for some reason !

I suspect corrosion rather than a blow if you haven't overheated it .
What had been the state of the coolant over the years ? This will have been a long term thing over many years ...

Good point Clan, potentially running OAT coolant and we all know how that ends!

[kiloran]

I've had the car about 18 months, it didn't have OAT coolant in it when I bought it, and I've only used the correct Volvo coolant in my ownership. Sadly this issue is all on me - work/family has been so busy these past few months that I've not had time to take a proper look at why it was losing coolant. The car was behaving, driving fine, not overheating, and only being used for short journeys so it just wasn't a priority. I'm guessing it's a small crack in the gasket that's just widened over time. We did a 200+ mile roundtrip on Friday in quite warm weather hammering (relatively speaking!) through the South Downs that's probably been the straw that broke the camel's back. Fortunately it's never overheated so fingers crossed we're all good and I'll make sure the garage checks tolerances and skims it if needed. School holidays upon us so I can afford to wait for the car and have it done properly. Timing belt and tensioner also being done (belt is due in 2k miles). Water pump was done shortly before I bought it.
Wondering - are there any other routine jobs worth doing when the head's off? It's not using oil excessively and hoses all look good. Rad was done last year.

[360beast]

Ideally it will want the valve hushers replacing, the cam, auxiliary and front crank oil seals and the front crank housing gasket too.

[Laird Scooby]

If the head is coming off, check it's flat and if necessary (or unsure) have it skimmed. Also do a full decoke and lap the valves in too then check the valve clearances (hushers out while checking) and adjust with different shims if necessary.

[volvo always]

Also clean the flame trap and breather box, while access is good.

Glad your having it fixed. I'd do the same with my 940.

James

[kiloran]

Well, sad news I'm afraid.

Well and truly had it, looks like it's been severely mistreated in previous ownership. Virtually all the coolant pathways in the head are completely corroded and blocked, as are many of the ones in the block. And the block face is heavily pitted. New head and block facing at a minimum plus there's no guarantee this isn't more damage we can't see. Mechanic said best thing was to pull the plug, particularly as she owes me so little. He was amazed that it wasn't overheating in that condition because all the pathways at the front of the engine were completely blocked

Not sure on next steps - partially dismantled so not driveable but a good source of parts. I don't have the space/time to break her and it's a shame to send her to a standard scrappy. I've got till the end of the month to get her off the road. I'm just south of Salisbury.

'93 940 2 litre SE, 7-seater, blue. Other than the dead engine she's in reasonable nick.