car eating the expansion cap

kevin · 24th June 2009, 15:58

sold my 1.8 as I had to get a auto. ( wish I never)

but again it let me down, this time on my way to work at midnight yesderday.

car over heating let engine cool took cap off put water in. went to have a look at the water today and the top of the cap came off leaving the rest in the expansion tank. agin had to order a new one. (75 off road again)

this will be its 3rd rad cap in 4 mouths lucky new cars a V6 or would have hgf by now.

any one know a reson why its eating the expansion cap.

Greeners · 24th June 2009, 16:06

No I can't answer that, but I'd change the tank now as well......I think Les may even have a new cap and tank in the shop

kevin · 24th June 2009, 17:26

Quote:

Originally Posted by Greeners

No I can't answer that, but I'd change the tank now as well......I think Les may even have a new cap and tank in the shop

Thanks, will try changing both this time.
Les has a s/hand one I can have for free. Les @smc help's again.

Simon · 24th June 2009, 18:25

Sounds like you have an underlying problem. The car should not be overheating nor should it require water.

Are there any signs of water leaks/orange stains on pipe work? Is the expansion chamber itself in good condition, ie not damage or deformed in any way?

How much are you topping up by? If you put too much water in then the system will simply 'dispense' with the extra volume. Normally the level sits about a third to half way up the expansion tank with the engine cold.

Finally (a lot of questions I know!) - are there any invoices from when you bought the car to indicate that it has already had work done on the engine for a similar type of fault?

kevin · 24th June 2009, 21:25

Quote:

Originally Posted by Simon

Sounds like you have an underlying problem. The car should not be overheating nor should it require water.

Are there any signs of water leaks/orange stains on pipe work? Is the expansion chamber itself in good condition, ie not damage or deformed in any way?

How much are you topping up by? If you put too much water in then the system will simply 'dispense' with the extra volume. Normally the level sits about a third to half way up the expansion tank with the engine cold.

Finally (a lot of questions I know!) - are there any invoices from when you bought the car to indicate that it has already had work done on the engine for a similar type of fault?

started after I had the lpg put in badly losing water all the time, this was down to the way it was pump in. air getting in because a part was fitted above the level of the expansion tank.
which Bernard lpg put right for me

a two week old cap fell apart when he was working on it.
all ok from then till I had a looked at the water on monday after doing 250 mile rould trip into the RBRalay.
cap was hard to undo put in 1/2lt of water.
on trip to work after 7miles car over heated. they was some water on top of the expansion tank. look like I may not of done the cap up. but again the cap was hard to undo and do up.
went to look at the water after work and the cap top came off in my hand leaving the middle of it in place.

as both yourself and david have said in may be a expansion chamber may be damage or deformed in some way.
will replace both this time.

Bernard LPG · 24th June 2009, 22:02

It seems to me that the design of the cap leaves a lot to be desired. If the bung part is tight in the tank then there isn't much to prevent the top of the cap coming away from it. Just some very small moulded plastic clips, it's like some cheap toy. I tried a trace of clear grease on the O-rings to help the bung move more freely but it obviously didn't work well enough.
Another expansion tank may not be quite so tight.

24th June 2009, 15:58	#1
kevin I really should get out more....... ford focus ghia Join Date: Feb 2007 Location: herts Posts: 2,553 Thanks: 0 Thanked 2 Times in 2 Posts	car eating the expansion cap sold my 1.8 as I had to get a auto. ( wish I never) but again it let me down, this time on my way to work at midnight yesderday. car over heating let engine cool took cap off put water in. went to have a look at the water today and the top of the cap came off leaving the rest in the expansion tank. agin had to order a new one. (75 off road again) this will be its 3rd rad cap in 4 mouths lucky new cars a V6 or would have hgf by now. any one know a reson why its eating the expansion cap.

24th June 2009, 16:06	#2
Greeners Moderator MG-ZTT Join Date: Mar 2007 Location: Ware, Herts Posts: 19,798 Thanks: 161 Thanked 1,249 Times in 1,036 Posts	No I can't answer that, but I'd change the tank now as well......I think Les may even have a new cap and tank in the shop __________________ *David* Impecunity is the mother of ingenuity Useful how to's for common problems Car Of The Month Jan 2014 [SatNav Power Down] [Coolant Level] [SatNav Repair] [Diesel Non Starting] [Paint Codes] [Rear Light Seals] [Reversing Light Switch] [Bleeding Brakes][Sunroof Drain] [Early ZT's][Instrument Pack Diagnostics][ATC Diagnostics]

24th June 2009, 18:25	#4
Simon Banned - Join Date: Nov 2006 Location: - Posts: 10,318 Thanks: 0 Thanked 4 Times in 3 Posts	Sounds like you have an underlying problem. The car should not be overheating nor should it require water. Are there any signs of water leaks/orange stains on pipe work? Is the expansion chamber itself in good condition, ie not damage or deformed in any way? How much are you topping up by? If you put too much water in then the system will simply 'dispense' with the extra volume. Normally the level sits about a third to half way up the expansion tank with the engine cold. Finally (a lot of questions I know!) - are there any invoices from when you bought the car to indicate that it has already had work done on the engine for a similar type of fault?

24th June 2009, 22:02	#6
Bernard LPG I really should get out more....... 75 V6 Saloon 2003 LPG MGZT V8 260 LPG Join Date: Dec 2006 Location: Evesham Posts: 2,134 Thanks: 0 Thanked 1 Time in 1 Post	It seems to me that the design of the cap leaves a lot to be desired. If the bung part is tight in the tank then there isn't much to prevent the top of the cap coming away from it. Just some very small moulded plastic clips, it's like some cheap toy. I tried a trace of clear grease on the O-rings to help the bung move more freely but it obviously didn't work well enough. Another expansion tank may not be quite so tight.