Radiator flush stuff (engine)

[octo0072000]

change the thermostat but check new one opens first in a pan of boiling water before fitting also change the water pump as well as the rad and temp sender unit
but after all that better sniff test it could be head gasket with being stood all this time

 

[julianf]

I'm loath to do the water pump as I've had bother from the p gasket before on 300tdi.

I'll put on what I've ordered (new rad, new thermostat, new sender) and I'll give it a good hose through, and then I'll see what it's like.

I don't want to just go "fixing" everything as half of it might not be broken.

 

[dextadriver]

Something I learned from a tractor mechanic is don’t fit new radiator as new radiators are crap… better to have old radiator reconditioned

 

[Domdom]

Right, no laughing you lovely bunch of peeps.

I've not long done a Ford Transit Connect diesel. Had the oil in water problem that goes with the oil cooler leaking into the water circuit. Nasty gunge everywhere, and I mean nasty. Heater stone cold, engine red hot, hoses solid.

I fitted a new oil cooler and then started with a back flush of everything I could get a hose into. Strong tap pressure, nothing more. Then refilled with fresh water and 2 washing tablets (Aerial Biological if it makes any difference). Ran the engine at idle for 30 minutes. Took the bottom hose off (yeuk) and then repeated the process starting with another backflush, 2 more Aerial tabs etc. Final drain, flush of the block and it was all like new. I had thought it might need a new radiator but the process brought the inside back to almost new condition with clear core pipes.

No Marigolds were harmed in the process above.

 

[winchman]

We use some stuff for heat exchangers it cleans them like new but its £200 for 25L! we use a heating system Proflush machine its fantastic

Home

proflush.co.uk

I believe the stuff for domestic heating is good?

 

[sako243]

To be honest the 300Tdi is such a simple beast to work on if you can spare an evening or afternoon I'd be whipping off the head, undoing all the hoses and as Rich says shove a hose pipe in every hole you can find until the water comes out freely and clearly.

Admittedly with a nice barn to work in but just a chain hoist off a beam I did a full head gasket, cam-belt, clutch, swapped the ancillaries and swapped the engine in 6h on my own.

Mind you I had just done another full engine swap on the same vehicle 5 weeks prior at @8ob's yard so I still had all the torque settings in my head

 

[sako243]

I'm loath to do the water pump as I've had bother from the p gasket before on 300tdi

As long as the surfaces are straight, clean and you use the later stamped metal gasket with a wee bit of sealant you won't have an issue. Never have after doing quite a few of them.

 

[julianf]

 

[julianf]

 

[julianf]

Thermostat was partially open when I was flushing though the system (hose, fresh water) so may, I guess, have jammed in the partially open (not fully open) position. I guess I could test the old unit in a pan, but I don't think I can be bothered.

It was clearly installed without care also, as the seal was all mangled.

Radiator wasn't healthy.

So, all I've done so far is flush out with the hose, change the radiator and change the thermostat.

Will see what happens tomorrow on the way back for the mot retest.

 

[tom2207]

probably be grand

 

[julianf]

My feelings are that the radiator alone wouldn't have given the symptoms I saw.

Sure, it's stuffed, and the day was crazy hot, but, if everything else was good, then driving along, with very cautious accelerator use, AND with the internal heater on - I'd have thought that even a very bad radiator would probably cope in those conditions. I mean the heater matrix in the blower unit would probably just about even up the missing fins on the main radiator. Or at least get close. And again I was driving as gently as I could.

So my suspicion is more the thermostat. Obviously combined with the radiator, but I just feel that the radiator alone wouldn't have had me having to pull over to cool it down every 6 mins or so.

If this doesnt work I'll do the pump. I don't know about the pumps, but in my prior experience they have always been a bit more binary (work / don't work) rather than an item that gets reduced performance?

But, yeah, it's got to be somthing. Hopefully it was what I changed today.

 

[tom2207]

My feelings are that the radiator alone wouldn't have given the symptoms I saw.

Sure, it's stuffed, and the day was crazy hot, but, if everything else was good, then driving along, with very cautious accelerator use, AND with the internal heater on - I'd have thought that even a very bad radiator would probably cope in those conditions. I mean the heater matrix in the blower unit would probably just about even up the missing fins on the main radiator. Or at least get close. And again I was driving as gently as I could.

So my suspicion is more the thermostat. Obviously combined with the radiator, but I just feel that the radiator alone wouldn't have had me having to pull over to cool it down every 6 mins or so.

If this doesnt work I'll do the pump. I don't know about the pumps, but in my prior experience they have always been a bit more binary (work / don't work) rather than an item that gets reduced performance?

But, yeah, it's got to be somthing. Hopefully it was what I changed today.

make sure its bled properly ,, they can be a pita some days ,,. and watch that plastic plug , they strip easily. and dont miss the alloy one with the copper washer ,,, quick feel of the two heater hoses will tell you whats going on .

 

[julianf]

Its bled, the heater matrix is hot, and there is some visible movement in the header. All the standard checks come back as you would hope them to.

 

[Tinbasherdan]

just bin the rad, new alu ones are cheap enough. a tdi shouldn't ever go beyond halfway up the gauge, on a cool day they shouldn't really get warm. as for not doing the water pump, the 300 is the easiest in the world to do, 20 mins tops. wouldnt bother flushing the engine either. unless somethings gone very, very wrong, i doubt itll be blocked up
edit: skim read and didn't notice you'd already bought a new rad. as bob said, check the gauge is working properly too

 

[octo0072000]

is the viscus fan working ? or not

 

[julianf]

Viscous fan seems spinny enough. I've not done further testing on it. I have a couple of spares so maybe I'll just swap it anyway.

Took it for retest today, after doing the radiator and themostat at the weekend and the overheating is equally as bad, if not worse.

Somewhat took the joy away from the MOT pass sheet.

Spoke to the chap at the garage who is familiar with 300tdis. Noone can know for sure but he said he had not seen a 300 water pump part fail. Ones on other cars with plastic impellers, sure, but, as per my own expectation, he said 300 pumps either worked or they did not.

I mean it's cheap enough to do, but I just don't see the logic in it at present. Again heater matrix gets hot. If I turn off the engine, the blower air goes cool after a couple of mins. If I start the engine again, the blower air gets hot again virtually instantly (ie as new, hot, water gets pushed into the matrix). We are talking a handful of seconds. This, to me, would imply a working pump.

But, yeah, somthing is causing it. I'm just not going to go changing the windscreen wipers unless someone can give me some sort of logical scenario where they would cause overheating.

I suspect I should do a exhaust gas test. But again I can't really see how head gasket failure can cause overheating until either the coolant is gone, or the gasses themselves have caused an airlock and stopped flow. Again neither of these has happened.

I've read on forums about different hoses getting blocked and causing overheating. I mean I'm only looking at flow through the heater matrix so I know that circuit is clear, but that's not the only pathway. And it's not even the main pathway. So if another house was partially restricted then that would account for the symptoms I'm seeing, I think.

Of course, it will be the pump in the end... ! : ). I'm just not sold on that idea at the moment.

 

[tom2207]

sorry to ask the obvious , but is it overheating and not just pressurizing the cooling system.

 

[julianf]

Bit of both. Well a lot of overheating and a bit of pressure. The hoses were starting to weep at the junctions on the way back.

But only as much as would seem in line with the coolant temperature. I did the scientific test of holding my palm on the headder tank top whilst giving it revs and it didn't build pressure then. But obviously that wasn't under load either.

 

[julianf]

I was driving cautiously and stopping etc so I didn't get a full on boiling event but I have no doubt that I wasn't far off. Touching the outside of the head (again after granny driving as much as I could) resulted in involuntary recoil. It should have been at 84c, which is probably about the heat of a cup of tea if you don't pre-warm the cup.