condensation inside distributor cap

E.Latto · Post by **E.Latto** » Fri Jun 18, 2010 9:14 pm

SD1 V8. If I switch off the engine before it is fully warm, then attempt to start 10mins or so later , it missfires due to condensation building up inside the distributor cap. Why is this and what can I do about it? Any ideas please?

ian.stewart · Post by **ian.stewart** » Fri Jun 18, 2010 9:21 pm

A good spray of WD 40 inside the cap and internals will sort that. also worth spraying the leads and plugs too

E.Latto · Post by **E.Latto** » Fri Jun 18, 2010 9:36 pm

Thanks for replying. I have never had this problem with any other car, and I have had 2 older Rover V8s as well, so why should this be?

ian.stewart · Post by **ian.stewart** » Fri Jun 18, 2010 9:42 pm

Probably water has got in the dissy[heavy rain with the bonnet up, going thru a flood or big puddle] only causes a problem when the engine starts to get warm

E.Latto · Post by **E.Latto** » Fri Jun 18, 2010 10:46 pm

No, this is a long-standing problem which occurs come rain or shine.

CastleMGBV8 · Post by **CastleMGBV8** » Sat Jun 19, 2010 7:40 pm

Where are you based?

I would agree with earlier suggestion that there is some water in the base of the dizzy, easiest way to check would be to take off the vaccum advance unit and have a look inside the bottom of the dizzy.

Also are you suggesting that once the engine is fully warmed up that the problem does not occur?

Kevin.

unstable load · Post by **unstable load** » Sun Jun 20, 2010 8:21 am

Are your cooling lines in good shape? I only ask because my Rover had a line rupture and it filled the dissy with water, so a pinhole could be a source of your misery if it's in the right/wrong place.

Back in my Mini days I used to seal the dizzy cap with silicone after a goodly squirt of WD40 or similar.

I swear by this stuff...
http://www.mr-mckenic.com/01.html
ever since I watched a guy spray it into the motor of an electric drill and then submerge it RUNNING into a bucket of water.

ChrisJC · Post by **ChrisJC** » Mon Jun 21, 2010 7:06 am

The other trick is to run a tiny (1/8th or 16th inch bore) pipe between the distributor cap (drill a hole) and the inlet. Then a small amount of air will be drawn through it.

Shouldn't be necessary though.

Chris.

jefferybond · Post by **jefferybond** » Wed Jun 23, 2010 3:38 pm

Maybe water in the oil due to a failing head gasket? Does the coolant need frequent topping up?

E.Latto · Post by **E.Latto** » Sat Jun 26, 2010 2:38 pm

Thanks all for your suggestions, and aplogies for late reply. Cylinder head is not leaking, niether are hoses. Once the car is fully warmed up, it can be stopped and then started again with no problems. Is there maybe some faulty seal on the distributor drive shaft letting warm moist air up from the crank case to condense against the colder cap?

RoverP6B · Post by **RoverP6B** » Sun Jun 27, 2010 4:23 am

E.Latto wrote,...

Is there maybe some faulty seal on the distributor drive shaft letting warm moist air up from the crank case to condense against the colder cap?

Hello E,

There would need to be considerable free play in the distributor shaft for this to even be a possibility.

Have you replaced the distributor cap?

I have been driving with a Rover V8 since 1985, and I have never had this happen.

The condensation that you find under the cap, when you wipe it off with a clean white rag, what colour is it? Does it have a noticable smell?

Ron.

DaveEFI · Post by **DaveEFI** » Sun Jun 27, 2010 6:52 am

E.Latto wrote:Thanks all for your suggestions, and aplogies for late reply. Cylinder head is not leaking, niether are hoses. Once the car is fully warmed up, it can be stopped and then started again with no problems. Is there maybe some faulty seal on the distributor drive shaft letting warm moist air up from the crank case to condense against the colder cap?

The crankcase should be under a slight vacuum with the engine running. The dizzy drive should have a film of oil which would seal it from moisture.