Ok this one is a bit of a question and later hopefully answer post.
For a few months I have been bursting various coolant hoses from the little turbo returns to the top hose with a massive 8inch gash and I blew the top off the radiator. The top hose burst on my way to the doctors with a broken rib, I had to patch it up, carry on to the doctors in agony then after being told to go straight to A&E as they thought it may have been pneumonia at the time before the xray showed it was a broken rib, I had to borrow water containers from the doctors to fill the car up to get it home, fun and games. The car also lost its water in rush hour on the M25 which was nice joining the AA on the roadside and being charger £200 for the privilege.
Anyway back to the point, I have heard a lot of people saying when one hose goes the others are shortly to follow so I replaced all of them.
The car has always spat out excess coolant and bubbled the overflow tank a lot but i thought this may be normal.
I also saw a lot of folks saying must be head gasket etc so I did all the leakdown/compression tests etc and it all checked out ok. One hose actually burst 10 minutes after parking as I walked past the car, I guess due to heat soak so leaking head gasket would have not affected that at all.
Trying to search for the problem I decided that a coolant swirl pot was a possible cure to remove the gas pressure more effectively. Most turbo cars need them and a lot get them from the factory as standard. Not seen many people here talking about swirl pots on VR4 engines. I will make a write up shortly about making the pot.
So I installed the pot and ran the car up. The vents were from rad top tank and one from each turbo return as these are the locations of most bubbling possibility from local boiling. I noticed there was no water coming from the turbos. Odd I thought. I took the hoses off and blasted compressed air back down them, the front turbo blasted out a bunch of bubbles after an initial blockage. The rear turbo however is totally blocked to the compressed air so I assume the pipe of housing is blocked too, for how long I have no idea.
I now think the hose issue was caused by this, either causing a pressure buildup down a narow pipe hat cannot release it quickly enough of if the turbo is hot and some water gets through it may immediately turn to steam and bang goes a pipe like throwing water on sauna rocks!
I need to remove pipes and possibily turbo to check this all out, so I will keep you informed of my findings.
Nick I remember you had a similar problem.
The question part, has anyone else had problems with blockages?
The coolant was full of a lot of brown dry crap that I had to go to town on flushing and 2 bio cleaners to get rid of it but the blockage has already been done. looks like th crap that forms when 2 coolant types mix. The car was like it when I got it, definately not oil in coolant.