Grumbling lift pump, went to have a look but....

Post by **Welly** » Mon Feb 26, 2007 9:51 am

My lift pump sounds a bit grumbly first thing in the morning. Instead of a nice 'whizz' it sounds a bit like a compressor, TBH I can't remember if it's allways done this or if it's got gradualy worse, or indeed whether it's temperature-related, as it does seem quieter later in the day.

I thought I would try to listen to it with the engine running to see if it changes. After restling with the seat bench (and finding 1 french franc, and an old blue biro) I found the fuel pump cover lid was sheilded by a black metal plate rivieted on (looks like a factory fit, very neat etc.).

I did manage to put my ear to it and listen and the pump was running consistently but I'm not sure if it's on it's way out or not or just leave it alone?

jameslxdt · Post by **jameslxdt** » Mon Feb 26, 2007 7:15 pm

have you changed your fuel filter welton, that might be worth a try, and have a look for metal particles in the housing, this noise maybe a sign of your lift pump becoming lazy, to your knowledge have you ever had it replaced?, could also be a sticky piston in the pump, does it idle slightly lumpy?

Post by **Welly** » Tue Feb 27, 2007 9:49 am

Fuel Filter was changed 12 months ago (7000 miles) Idles sweet. Only really grumbles first off.

You know if the lift pump craps out, will all the fuel lines need purging out? will any 'bits' make it into the HP pump

?????

jameslxdt · Post by **jameslxdt** » Tue Feb 27, 2007 9:07 pm

ideally you should replace the entire fuel system like peugeot recommends, it may seem like they are ripping you off, but they are just covering themselves, if they just changed the lift pump, and the HP went like a month later, who would be to blame?

Post by **Welly** » Thu Mar 01, 2007 7:35 am

I think the grumbly noise may be temperature related. When the outside temp is low a thermostatic element in the fuel filter housing opens to allow the fuel to be preheated via the water system.

I notice that I get a high pitched noise from the engine bay went the fuel pump first kicks in which would be the fuel passing through this thermostatic bypass, this would create back pressure on the lift pump so it has to work harder, you don't really notice this on warmer days.