Oh Dear

plastic orange · Post by **plastic orange** » Mon Jul 20, 2009 3:45 pm

The 3.9 engine in my newly refurbed Minor used a lot of water on a 200 mile trip at the weekend to a car show. Power and running as normal - temperature below 80 as usual, but increased quickly when in traffic (unusual). It cooled down with fans on to below 80, but on investigating I noticed a loss of coolant from the header (expansion) bottle. I topped this up, and on the run home was again fine, but I needed to put in about 3 pints of water when I checked today.
I fired it up today (ran as normal) and allowed it to tickover for 30 minutes to see if it got hot. As soon as it got to 80 I turned the fans on and as usual it dropped under. I then gently released the pressure cap - and no pressure.
Normally, the pressure in the expansion bottle remains there for a long time - sometimes weeks after not being run. Today I did a compression test, and all returned 150 - 160 (9.35 - 1 engine) which I thought was fine. I observed the first turn over, and nothing came out any cylinder - and they all seemed dry. However, number 2 plug on the N/S bank was a slightly lighter colour than the rest (normal colour after a run, but car was ticking over before checking).
Oil is still clean, and no emulsified oil in filler area, and no steam or blue smoke from exhaust.
Is the consensus a gasket, or a liner? (be my luck if it is).
What's my next step? - only spent the last 2 months tidying the thing up

.
Don't tell me to put my LS1 engine in it

- that's my other project.

Cheers

Pete

ian.stewart · Post by **ian.stewart** » Mon Jul 20, 2009 4:06 pm

Go the easy route first, change the rad cap, have you replaced it recently, because there are generally 2 different lengths, fit a short cap in a long receptical and it will not pressurise,
If the engine is not a X bolt or have X bolt bosses I would doubt if it is a liner problem, I had loads of problems with water leaks, turned out to be the foam inlet gasket had delaminated and was allowing water to seep thru,

plastic orange · Post by **plastic orange** » Mon Jul 20, 2009 4:13 pm

Cheers - it is the same rad cap I've had for years, but the inlet gasket is about 2 years old, and is the black 'foam' type.

Pete

CastleMGBV8 · Post by **CastleMGBV8** » Mon Jul 20, 2009 6:44 pm

Pete,

If it's losing coolant the first thing I'd try would be a new cap,

If the card been standing idle for some time then the rubber washer could have lost it seal or the springs gone weak and the coolant is just blowing out from normal pressuriation.

If it still does it you could have it tested for hydrocarbons in the coolant which will tell you if it's head gasket or the dreaded cracking behind a liner, but as Ian said it's not very common on the earlier engines which haven't been run as hot or as lean as the later ones.

Kevin

plastic orange · Post by **plastic orange** » Mon Jul 20, 2009 6:48 pm

Cheers,

I'll give it a go.

Pete

volospian · Post by **volospian** » Tue Jul 21, 2009 7:29 am

It's also worth checking your hoses! I lost coolant in the TVR when a pipe split. Luckily it must have gone just as I got home as there was no sign of overheating, just a large puddle forming under the car when I got out. Anyway, I changed the hoses and took the car out for a test run. The temps stayed fine, the engine ran fine, but I still seemed to be losing a bit of coolant.

I had it booked into the garage for some other work anyway, so, fearing the worst, I took it over. I was wondering if the initial loss of coolant had caused localised overheating/warping of the heads or something as I couldn't see where I was losing coolant.

Anyway, Paul had a good look around and found that one of the jubilee clips wasn't quite tight enough. It was fine when the system wasn't pressurised, but when it was hot the water was squirting out. I still couldn't see it on the drive because it was spraying onto the exhaust and evaporating rather than dripping.

So.... to cut a long story short, check for splits in the hoses, and the condition of the clips...

Richard P6 · Post by **Richard P6** » Tue Jul 21, 2009 10:40 am

Sounds like a hose problem to me - you have a few of them too.

I had a top hose develop a pin hole at its highest point so was difficult to notice unless you were revving the engine.

Have you got the fan sensor inside the top hose as these can leak.

Check your heater hoses too, inside the car as well.

Mine is leaking at the moment and a small pool is forming in the valley gasket. I am sure it is from the top hose or the little transfer hose but am having a devil of a job actually stopping it.

volospian · Post by **volospian** » Tue Jul 21, 2009 11:10 am

By the way, Pete... nice motor!!

ChrisJC · Post by **ChrisJC** » Tue Jul 21, 2009 11:38 am

Richard P6 wrote:
Mine is leaking at the moment and a small pool is forming in the valley gasket.

Make sure it's not just rain gathering there.....

Chris.

plastic orange · Post by **plastic orange** » Tue Jul 21, 2009 3:24 pm

Hoses were the first thing I checked - no drips anywhere, and valley gasket dry too.

Pete

kiwicar · Post by **kiwicar** » Tue Jul 21, 2009 3:53 pm

With that loverly big engine bay of yours, wouldn't a nice cadillac northstar engine nestle in there a treat? Swap the heads over left to right, you would have the hight undre the bonnet to mount a pair of turbos above the valley and get them plumbed in look very smart!!

Mike

plastic orange · Post by **plastic orange** » Tue Jul 21, 2009 4:10 pm

I've got an LS1 motor for my other Minor.

Pete

kiwicar · Post by **kiwicar** » Tue Jul 21, 2009 4:13 pm

two minors, two different engines, you don't want them all the same do you?

Mike

plastic orange · Post by **plastic orange** » Wed Jul 22, 2009 4:17 pm

I fitted a new rad cap then went for a quick run of around 15 miles - temperature as normal, but when I came back water was pissing out the overflow - obviously pressure there now

Looks like I'll get a sniff test done, then go from there. I'd quess it must be a head gasket as a knackered liner would be dumping water in the sump (I presume).
On my run to the car show, the water must all have been gone when I got to my destination - hence no signs.
Engine still running as normal.

Pete

ChrisJC · Post by **ChrisJC** » Wed Jul 22, 2009 9:00 pm

No, knackered liner doesn't put water in the sump. It disappears out of the exhaust....

Chris.