Combustion leak solutions please

[Hoopy_Frood]

On our first foreign holiday, I needed to bleed the radiator at approximately 400 mile intervals. It looks to be fairly predictable, in that it doesn't just shoot up, but the needle starts to move slowly up and the fan no longer kicks in. Bleeding the radiator offers at least a temporary fix as the fan comes on again once all the air is out of the system.

I'm reasonably sure (after extensive forum searching and having tried a few brickwerks-recommended style bleeds) that I have a combustion leak. It's had two bottles of
K-seal put in over the last 18 months, but I have to accept that this is no longer working.

Apart from the overheating and a largish oil leak coming from somewhere, I think the engine is still pretty strong (although I have no other reference points to work from) so I'm wondering how feasible/economical it is to fix it up rather than go down the replacement engine route?

Do these types of leaks usually come from the head rubber seals or are there any other culprits?

If time and money were not an issue, I'd likely go with a petrol to TDI conversion, but since the quote I got for that was the same as we paid for the van, it's not a real option.

[ghost123uk]

Do these types of leaks usually come from the head rubber seals or are there any other culprits?

OK, first thing is, leaks from perished rubber head to case seals are nearly always visible as dripping coolant, or at least crusty deposits where the antifreeze has evaporated away, in the area of the leak. Do you have any signs of those symptoms?

Secondly, combustion gasses in the left hand white header tank can easily be "sniffed" by any half decent garage using their exhaust gas analyser. That will tell you right away if you have a leak from combustion chamber to coolant system and won't cost hardly anything (to test).

Next question = how often do you have to fill up the expansion tank (the white tank on the left hand side)?

Your problem could be a simple coolant leak. The sniffer test mentioned above will tell you. If you get the all clear in that respect, look for signs of leaks.

Oh, K-seal has a habit of blocking up the "Dalek" cap on the expansion tank. This can cause it to malfunction and dump coolant into the other tank (the "top up tank", but not suck it back again as the engine cools down). Tip = wrap insulation tape around it's stub tube so it fits tightly into a bit of garden hose (attached to a tap) and blast it through a few times. You will like see some muck come out. They are supposed to be "one way", i.e. you can blow down that stub pipe (with you mouth) but not be able to suck.

[Hoopy_Frood]

OK, first thing is, leaks from perished rubber head to case seals are nearly always visible as dripping coolant, or at least crusty deposits where the antifreeze has evaporated away, in the area of the leak. Do you have any signs of those symptoms?

The top of the engine has quite a lot of white crusty bits on it, mostly around the area near the water pump and left hand side of the engine. I'll post up a piccie when I get home tonight.
I've not noticed the coolant dripping out the bottom of the engine, although I might have been distracted by the dripping oil...

The expansion tank level seems to stay pretty much constant. I've only ever needed to top up the tank behind the number plate as this is quite often empty. On long runs, the level in this tank goes up significantly, to the point that there can sometimes be small amounts of coolant forced out from the cap.

I'll get it sniff-tested at my local mechanics too.

[ghost123uk]

The top of the engine has quite a lot of white crusty bits on it, mostly around the area near the water pump and left hand side of the engine. I'll post up a piccie when I get home tonight.

Well that could easily point to your problem and if it's to do with the water pump, or a nearby hose, you will be very happy (compared to the other things it could be !!!!!)

The expansion tank level seems to stay pretty much constant. I've only ever needed to top up the tank behind the number plate as this is quite often empty. On long runs, the level in this tank goes up significantly, to the point that there can sometimes be small amounts of coolant forced out from the cap.

That is quite normal. It is supposed to rise when the engine is hot, then drop again as the engine cools.
Worth noting that the "top up tank" behind the number plate is not sealed, it is designed to gently overflow if it gets too full.

I'll get it sniff-tested at my local mechanics too.

[Hoopy_Frood]

I managed to get some photos of the crusty bits of coolant - there's a lot of it in the engine bay, particularly near the water pump and the left head seal, but it's pretty much everywhere. How bad does it look to expert eyes?











If this is going to be another big problem (like my oil leak from the flywheel seal), at what point would it worth trying to get a new engine?

[Aidan]

that engine looks pretty good externally, and if it drives ok and doesn't sound too tappetty may be fine, but obviously till case is split you just don't know, but usually best long term if not nevessarily cheapest option is to get yours rebuilt once it is confirmed products of combustion in the coolant but it does point at that
I'd rather get my own engine refreshed than do exchange, I did that with Elite and the good ones were my known cores and they are all still running around upto 10 years later (Big Mick [rip] builds)

update the cooling system to late while you are there for longer term parts availability

[Hoopy_Frood]

The results from the sniff test came back positive. I knew it was pretty likely but damn, it's still painful to find out for certain.


I'm all over the place trying to decide what route to go down. I really want the van to be a reliable runner that I can actually use instead of just something to stare at on my driveway while I try to triage the list of things that need fixing on it.


If reliability were the main priority and a sub 2k conversion cost a fairly close second, what engine would you put in a family camper that will be used regularly?

Thanks

Iain

[kevtherev]

A DG 1.9 or a DJ 2.1 (using your DG ancilliaries & carburettor)
From a working van.

That would be my choice.

[ghost123uk]

Hi Iain, sorry to hear your motor is poorly.

If reliability were the main priority and a sub 2k conversion cost a fairly close second, what engine would you put in a family camper that will be used regularly?

I was in a similar boat around 7 years ago when my engine went sick. In my case I had a bit of a nightmare. I bought a supposedly "perfect DG" from a company called Eastfalia that turned out to be a totally worn out DF when it arrived. I got my money back, eventually I then tried to get my DG fixed up locally, but that went all pear shaped and cost me a lot of time, hassle, money and a broken friendship. All in all I fitted and removed one or the other of those engines about 4 times, in the winter, on my driveway

Now I was just unlucky, many folk have bought a used engine (often from here) and been fine

I was about to give up on T25's when Billy739 in Bristol (T25 breaker, off here) offered me a used DG that he reckoned was a good one, and it was and it is still going strong

I mention all this because, if I was ever to have to do it all again, actually I would buy the bits required to fit a Golf/Scirocco/Passat motor. They work well in T25's, they are reliable, economical, easy to fix and also they are plentiful in the breakers. There are a few on here that have done this ("Elvis" etc). Also certainly a heck of a lot less than your 2K budget (you just need a few bits of a Diesel T25 = easy enough to source) and a motor (say £250 for that).

Just another option to consider.

[Smosh]

Ghost, is that the petrol engine? what is required? Diesel bellhousing?

[ghost123uk]

Ghost, is that the petrol engine? what is required? Diesel bellhousing?

Yes, petrol. I'm not "the" expert in this at all, but iirc, you need the bellhousing, engine cross beam, sump, and a few other minor bits (off a Diesel T25) to fit one.

There is plenty on here (and on Brickyard) about doing it.

[Smosh]

thanks, I will have to look into this more. I have or the wife has! ruled out Subaru conversion because of the cost.