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Mixerfistit

Member

Registered: 2023-02-28

Posts: 56

Hot vacuum solonoid

Anybody know what the solonoid next to the coolant tank is for.

There's 2 hanging under the scuttle on my 2.0 HDi. The left one near the PS fluid tank is cool. The one by the coolant is too hot to touch for more than 2-3s noticed it was loose on the bracket so went to tighten it up.

To clarify it's been idling for 30 mins while I was doing some other jobs so not sure if it's hot when driving and it doesn't seem to be heating up when engine off but key on 2nd position. Edit - it takes about 2 minutes of engine running to go from cool plastic to uncomfortable so probably 3 minutes to hot.

I'm guessing the solenoid is stuck on or shorting

Extra info for any Columbo's in the audience..
On a cold start I think I can just about hear the turbo during the lower gear changes/ as the higher revs drop so maybe a waste gate controlled by this?

I also get a stiff brake pedal if I pump the brake quickly about 5 times with engine on although it recovers within a second (noticed in the winter before I replaced my abs ring and and to slow on icey roads the old fashioned way)

On a cold day after idling for a few minutes (no smoke on start) I get some grey white smoke that disapates into the air fairly quick and then stops once the engine has warmed up more so possibly Egr? (seems too smokey for condensation)

So I know all of these things rely on vacuum (I think the egr does anyway) but have done no fault finding on them as the vacuum hoses seem to disappear into the abyss and now I've found this hot solonoid I'd like to rule out whatever it's controlling.

Last edited by Mixerfistit (2023-07-01 15:27:21)

Mixerfistit

Member

Registered: 2023-02-28

Posts: 56

Re: Hot vacuum solonoid

It seems a bit more searching has uncovered an answer to the original question by quoting @JohnDragonMan

"the solenoid on the left controls the EGR. the one on the right controls the waste gate."
https://dispatchexpertscudo.org.uk/foru … hp?id=1438

So looks like a replacement is required. Maybe swapping them in the meantime is better?

If anyone else also wants to chime in with the other little gripes I mentioned, by all means you are welcome.

AlvyLad

Member

Registered: 2021-06-11

Posts: 479

Re: Hot vacuum solonoid

the whole EGR "invention" is a waste of time, at least for non turbo engines https://dispatchexpertscudo.org.uk/foru … php?id=715 complete isolation is as easy test as to replace anything only to find that EGR valve is actually faulty...
have a look at how to isolate and it might be solution or it might not