Water Pump/air leak

[DaveP]

My poor little 845tl is still overheating at speed, it's absolutely fine stop starting round town and driving country roads up to 90kmh, but when I go above 90 it seems to overheat really quickly. It's not a head gasket failure, that's been checked but I was thinking it could be an air leak. A quick WD40 check seems to give the all clear but it might make sense if it was only leaking at high engine speeds. My other thought was a possible waterpump fault, rusted impeller perhaps, seems smooth enough so I don't think the bearing has gone. Anyone had anything like this?

Thanks

Dave

 

[malcolm]

Overheating at speed in the summer suggests not enough cooling capacity for the engine as it gets near maximum power. A blockage of some sort would be my guess.

Maybe the radiator - if it's very blocked inside it can cause issues. Otherwise perhaps a thermostat that is sticking partly closed, or on some cars the bottom hose can collapse when it gets hot, but the 845cc ones should be too short for that. A water pump problem would seem less likely.

 

[DaveP]

A collapsed hose would make sense, it seems to overheat more quickly when the heater is on, which would allow the hose to collapse quicker, They're all a bit crusty in any case so I'll replace and get back to you. The rad looks ok, I've flushed it a few times. There's no thermostat fitted (I'll put one in for winter)

Thanks for the help

Dave

 

[DaveP]

Got the engine hot today then revved it with the bonnet open and sure enough the hose collapses. New one on order

Cheers Malcolm

 

[malcolm]

Wow. I didn't reallise the 850s would do that. I've had worries about the 1108 bottom hoses before - the design of those seems really bad. I've never had one collapse though.

I had the trouble with an ex-girlfriend's Peugeot 205. Real pain to diagnose as you only normally see the trouble after running for a while, and then you don't tend to be looking in the engine bay. Lotus Engineering's engine department diagnosed that one.

 

[DaveP]

It's nice to find the "big" problem you've been wondering about for months is a 5 quid bit of hose. I suspect the last owner (who had let the rad gum up) removed the thermostat to improve cooling but when I cleared out the cooling system it allowed more flow and the increased vacuum from the waterpump collapses the hose. It's fine at 85kmh but I've put tomorrow aside for the starter and for this. Wish me luck

 

[pepper]

Good luck with the starter, its not too bad a job, just very difficult access.

 

[mr-reno-139]

overheating could still be blocked rad does it feel warm all over ?
most cars will collapse softish bottom hoses if revved hard with no t/stat
all my sons race cars we take centre part of stat out only
think 845cc starter is easy with only 2 bolts even on lhd cars with steering in way

 

[DaveP]

Amazing, I can start anywhere I like now. What an unbelievable faff around though, not like the old ford.

Mr Reno you were spot on, I'd never really considered how restrictive the thermostat is, put it in and it's solved the hose collapse so I'll leave it be for the moment.

On another note, I'm convinced I have the quickest stock 845 in the world, I keep seeing threads about top cruising speed being 90 kmh etc, I had mine cruising at 120kmh on the mway quite happily for an hour today and she saw (indicated, and most likely optimistic) 140 on the flat before I gave her a rest, just to see you understand. She's had a diet of 80 to 100km trips 6 days a week recently which really seems to have blown out the cobwebs.

Thanks for all the help chaps

 

[DaveP]

Must have left the bolt on the engine mount (the one over the starter motor) loose. Had a bit of a knock pulling away from a junction today. Sincerely hope I've not broken anything. Is this likely to have caused any grief? Other than meaning I have to redo the whole procedure of course, which will be a barrel of laughs.

 

[jjad]

Dave,

it turns out that we had been driving around for a long time without the bracket at all! No damage done, although the clutch cable had been 'polishing' (rubbing on) the steering column!

 

[DaveP]

Really? I get a hell of a knock everytime I pull away reasonably "vigorously" and some odd rubbing sounds under acceleration. Mechanics hat on today I think.

 

[jjad]

Yes, though it was difficult to drive, especially pulling away in first or reverse: it took a lot of skill to prevent it from juddering. The problem was intermittent though.

Good luck!

 

[DaveP]

Seems to be the inlet manifold fouling the steering column. My mecano friend says it's common practise for the support bar to be thrown away at first service on 4's as it's a pain to get at the stuff underneath, apparently there's a heat shield under it as standard too. He was on the production line at bilancourt court and reckons it was the best car he worked on, mind you he was on Express vans for 5 years.