S80: General Sender unit problems

[Rangers789]

Hi. I have a 2007 S80 D5 and after intermittent instances of the car not starting (would turn over but not start) had the sender unit replaced. The same issue persisted and the garage replaced the unit again. And...the issue continues.An AA guy had seen the problem before and showed me how to hit the fuel tank to release something and in most cases, ilthe car then starts! I can’t continue to do this or spend ££ without getting a long term fix. Does anyone have any ideas and suggestions as to what is causing the persistent failure? Thanks in advance

[Clan]

Originally Posted by Rangers789

Hi. I have a 2007 S80 D5 and after intermittent instances of the car not starting (would turn over but not start) had the sender unit replaced. The same issue persisted and the garage replaced the unit again. And...the issue continues.An AA guy had seen the problem before and showed me how to hit the fuel tank to release something and in most cases, ilthe car then starts! I can’t continue to do this or spend ££ without getting a long term fix. Does anyone have any ideas and suggestions as to what is causing the persistent failure? Thanks in advance

do you mean the engine would not start because there was no fuel and the sender was stuck showing some fuel ?

[Rangers789]

Originally Posted by Clan

do you mean the engine would not start because there was no fuel and the sender was stuck showing some fuel ?

There was plenty of fuel in the tank and engine turns over. Just doesn’t start - unless I whack bottom of fuel tank! Thanks for your reply and question.

[SwissXC90]

Piossily clogged filter or stuck fuel pump

Replace one then the other...

[green van man]

Isn't there an in tank pump on these ?
Sounds to me as if it's a pump that doesnot want to start, which could be crud or just worn out.
It realy depends where this pump is, confess I do not know but have come across some where it's biuld into the sender unit. As 2 of these have been changed if the pump is in the sender unit then it has to be either filter (which I would expect to be on the same unit) or wireing to the pump.
If the pump is seperate I would be looking to hoik it out and have a look see. In fact were it mine I would assess condition of pump and dependant on price put a new one in if there was any doubt.

Fuel filter is about £32 I think so not going to break the bank compared to the in tank pump and would do no harm to change.

Paul.

[Rangers789]

Originally Posted by SwissXC90

Piossily clogged filter or stuck fuel pump

Replace one then the other...

Thanks for your reply and suggestion - very helpful.

[Rangers789]

Originally Posted by green van man

Isn't there an in tank pump on these ?
Sounds to me as if it's a pump that doesnot want to start, which could be crud or just worn out.
It realy depends where this pump is, confess I do not know but have come across some where it's biuld into the sender unit. As 2 of these have been changed if the pump is in the sender unit then it has to be either filter (which I would expect to be on the same unit) or wireing to the pump.
If the pump is seperate I would be looking to hoik it out and have a look see. In fact were it mine I would assess condition of pump and dependant on price put a new one in if there was any doubt.

Fuel filter is about £32 I think so not going to break the bank compared to the in tank pump and would do no harm to change.

Paul.

Thanks for your reply and advice. Really helpful! Thanks

[Clan]

Originally Posted by Rangers789

There was plenty of fuel in the tank and engine turns over. Just doesn’t start - unless I whack bottom of fuel tank! Thanks for your reply and question.

ahh right , you better get a new in tank pump , that will sort it out .

[Rangers789]

Originally Posted by Clan

ahh right , you better get a new in tank pump , that will sort it out .

I believe the fuel pump is part of the sender unit which worries me as after 2 new sender units, it’s still failing. Wondering if I need a new tank or perhaps it’s an electrical fault? Thanks again for your reply.

[Clan]

Originally Posted by Rangers789

I believe the fuel pump is part of the sender unit which worries me as after 2 new sender units, it’s still failing. Wondering if I need a new tank or perhaps it’s an electrical fault? Thanks again for your reply.

The terminals on top the sender for the fuel pump can overheat , try replacing the plug and terminals on the car loom plug .