Head gasket.. maybe ..

Doug

Member
Hi me again

Engine is losing water, but not quickly.
Small amount of mayo in the oil filler cap.
Removing the water filler and viewing the radiator coolant: If I blip the accelerator, it doesn't bubble or surge. Seems fine.
Water pressure seems ok.

so .. somehow water is getting in the oil, gradually, but it's not behaving like a 'normal' blown head gasket.

Is there any other way the oil / water can mix?

note that I've just added a thermostat which was missing before. Pretty sure that joint isn't leaking but could be relevant.
 
Sounds just like my Commer, except I dont get the mayo, perhaps because mine is vented to the atmosphere.

Is your engine vented to the intake?
 
Mayo is usually caused by the moisture condensing on the coldest point in the engine - the rocker cover. Most likely caused by short trips and the engine not getting really warmed up for any length of time, as dodgeram has pointed out venting the rocker cover to atmosphere should sort it.
 
Aha- yes the oil vent still goes to the air intake. That would add to the moisture-in-rockerbox?

I hadn't thought of that, thanks Dodgeram !

I'm using him to drive to work which is about 9 miles each way. He gets warm but only just by the time I get there.
Perfect journey for such moistness ?

That's two reasons to vent it to 'outside', the other being that when I slightly overfilled with oil, the air intake got severely ganked up and blocked with oil.
managed about 15mpg one trip which alerted me something was up lol

Hope I haven't bored you with all these questions, you're really helping out, and I feel as though if we end up at a campsite somewhere sometime, I should shove some beer in your direction(s).

thanks again.
 
No problems at all.................YAWN;) Connecting to the filter wouldn't add moisture it's just not the best way of getting rid of it - especially if the filter is choked up.
Beer is always good, more questions so I can build up the booze bank please:)
 
Breathing to atmosphere isn't ideal though. Sometimes at the lights (depending on the weather conditions) other drivers are looking around at a mysterious cloud like vapour floating around from somewhere...:oops:
 
Ideally it should be connected to the inlet manifold via a PCV. I did something similar on Bonnie but just connected the breather to the vac connection on the SU and it worked great but the engine didn't really like it, ran very lean (even though I turned the mixture right in) and the temperature of the gases being drawn into the were very hot so not doing the efficiency much good. I'll probably have another go but this time fit a restrictor - or a PCV.
 
Dodgeram - presumably that's only if the engine is breathing a bit (worn rings) though? Or is that still the case on a squeaky new engine ?

Still can't work out where all the water is going. no sign of a leak, and it's now getting worse. I put a couple of pints in to top it up yesterday and today.
- but the oil isn't getting any more mayonnaisey than it has done (just a bit in the filler cap) and the water isn't under any particular pressure.
Mysterious.
 
Have a look underneath and see if there's anything dripping from the gearbox bell housing - hopefully not.
 
Have you tried a compression test yet?

No I haven't, good point.
Although if the water isn't pressurised then I suppose it may not reveal anything. Wouldn't hurt to do a test though.

re "Have a look underneath and see if there's anything dripping from the gearbox bell housing - hopefully not."
- I guess this is looking for a cracked block ? gulp ..
 
I think Mr.Panky may have been refering to a known to be troublesome core plug behind the flywheel rather than a cracked block.
Personally, I like to check the compression regularly (as well as for bubbles in the rad) and readings vary slightly over time with number one cylinder generally the lowest, in my case.
 
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I sounds like it could be the rear core plug if not going into the oil, fairly common to happen. The one at the rear of the engine rots through, pain to get to
 
Yep that's what I was pointing you towards. As Jim says a pain to do as the gearbox and flywheel has to come off. Compression test is a definite first.
 
Ah I see- didn't know about that plug. ugh what a pain!

I haven't seen anything dripping but will check for it. I'm suspicious of my thermostat replacement, but there's no dripping around the casing etc.. might be that the water is evaporating too quickly.

We have a o/d gearbox to put on at some point anyway so can have that core plug checked then

He's my daily driver at the moment until I can get my moggy MOT'd. Just needs to last another week or two .. then it's off to a classic car garage for loads of stuff:
o/d gearbox (& core plug check)
replace windscreen (at least the seal)
underseal
and I was going to have my grimace replaced with an admiring look.
 
Them thermostat covers can go porus, Doug, I borrowed one off a Ford Ka.

zoiks! and that is a very good tip, thanks because the cover was in a right old state. Only just enough 'pipe' bit left to get the rubber hose on.
 
Another thing to check is the rad cap. Make sure it's the right length and the seal isn't split or damaged.
 
No water drippjng from under van at all - phew!
But... mystery solved. Water is pressurised after all (radiator cap was holding it in i guess), so looking like it's the head gasket. I guess it must be leaking into the cylinder or something cos the oil still isnt all that mayonnaisey.
this also might explain shy there was no thermostat, to keep the water cooler. Probably worked ok until i put a thermostat in lol.
Oh bum.
 
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