Rover V8 with oily coolant

[100srv]

A tale of woe regarding a 3.9 litre Rover V8...

I checked the coolant level in the radiator last week and noticed that there was an emulsion in the cap, the coolant smelt funny. The next day I used a rag wick to dip the coolant; it came out oily and black. I drained the cooling system and refilled it with water and some system flush as directed on the bottle. I drove the car around for a bit and drained it again – hot, smelly dirty water came out. I then refilled the system with water and antifreeze (about two litres). Since then I have driven it about 50 miles. I want to see how quickly it gets dirty again (I suppose I am hoping that it is residue that has got flushed out over time and not a knackered engine), I am going to have a good look at the coolant on Saturday morning afer a long drive.

Since the oil is getting into the coolant but no the other way around I reckon that the fault is near the front of the block / engine. I suppose that a cracked cylinder head is most likely? Out of curiosity, when the cylinder heads were skimmed 0.006” was removed; is this a typical amount to remove?

Which suppliers would you recommend for replacement cylinder heads?

cheers
100SRV

[Liszt]

Might not be the head, could be a crack in the block or a knackered liner. Some people have tried using block crack type additives with some success. Your engine though, don't blame me if it turns in to a coffee table

[tr7v8]

100srv said:

A tale of woe regarding a 3.9 litre Rover V8... Since the oil is getting into the coolant but no the other way around I reckon that the fault is near the front of the block / engine. I suppose that a cracked cylinder head is most likely? Out of curiosity, when the cylinder heads were skimmed 0.006” was removed; is this a typical amount to remove? Which suppliers would you recommend for replacement cylinder heads? cheers 100SRV

Rare for heads to crack, more likely a shifted liner on a 3.9 unfortunately. Oh & 6 thou is nowt, mine have been skimmed 40 thou or 1mm!

[GreenV8S]

If the cooling system isn't getting pressurised then this suggests that it is just oil/water rather than water/cylinder. I would guess at HGF as the most likely cause. You may not see water in the oil because the oil gets hot enough to boil this off, oil in the water is a more obvious sign.

[100SRV]

Thanks GreenV8S, I am hoping it is headgasket failure; the coolant had oil in it but there doesn't seem to be a major loss as yet. I am going to dip the coolat in a bit with a piece of cloth wick to see whether the oil has come back...

Two years ago it was losing coolant really badly - this was the reason for the head skim - the coolant was becoming pressurized and ejected! The heads were skimmed .006" and refitted with tin gaskets. There were tell-tele signs of pressure loss towards the valley of the engine so when I rebuilt it, I torqued the ten combustion-chamber straddling bolts as recommended and the four outer ones to 30 lb.ft. only. Was this a good idea?

Thanks for the advice; I do hope it isn't a loose liner.

100SRV

[number 7]

100SRV said:

Thanks GreenV8S, I am hoping it is headgasket failure; the coolant had oil in it but there doesn't seem to be a major loss as yet. I am going to dip the coolat in a bit with a piece of cloth wick to see whether the oil has come back... Two years ago it was losing coolant really badly - this was the reason for the head skim - the coolant was becoming pressurized and ejected! The heads were skimmed .006" and refitted with tin gaskets. There were tell-tele signs of pressure loss towards the valley of the engine so when I rebuilt it, I torqued the ten combustion-chamber straddling bolts as recommended and the four outer ones to 30 lb.ft. only. Was this a good idea? Thanks for the advice; I do hope it isn't a loose liner. 100SRV

I think it's now fairly common to use studs rather than bolts to secure the heads, although I'm not sure of the torque figure. My 14 bolt heads have these, and the outer row of 4 bolts not used at all.

7.

[100srv]

Hello all,
car has covered about 300 miles of hard use since my initial post regarding the oily coolant. I will keep an eye on the engine but think the dirt and smell was probably residue from when I put some stop leak in (had a trawl through the maintenance log and found that little gem!).

Cheers
100SRV

[100SRV]

Oh dear, I checked the coolant level this evening prior to taking the car to Devon for the weekend; it is now milky coloured and smells oily. Off with it's heads...