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Cleaning EGR valve and throttle body


Staff member
Feb 24, 2010
Country Flag
I got all the gaskets for cleaning up the EGR valve and replacing the injector seals yesterday and decided today was a good day for this....

Getting to the injectors was easy except for the last bit, I could not undo the fuel line to the injector so could not continue with it :(
I cut a slot into a ring spanner to get around the nut but the ring was not strong enough and as I applied some force to it (I had porridge this morning) the ring split open. Cheap tools.....

So abandoning the injectors due to lack of tools ( :oops: ), I continued onto the EGR valve. I had a lot of soot in it, the valve itself was caked with stuff. Not sure if this is normal? The valve still opened and shut and you could feel air through the pipes when opening it so the diaphragm must be ok.
Scraped what I could off and cleaned the rest with thinners and an old paint brush. It's black. Very very black.

After cleaning it all and putting it back together, with new gaskets etc, all seems well. The leak which prompted all of this, so far, seems well. I was a bolt that was not tight. Toyota wanted to replace the whole EGR valve...

Some pics:

Leaky ERG valve:

Wobbly plastic cover: Off





Not exactly the biggest job ever undertaken on an LC but I was bricking it for a lot of the time putting stuff back together.
Not really sure if there is any difference after doing this.
I was bummed I did not get to do the injectors but this job was rather educational so not a waste :geek:

With thanks to Locrep for lending me a stronger looking ring-spanner mod, I will have attempt two...
Great - you're becoming a dab hand here ...

OK - question for the work-challenged (I'm at work again, so can't go open my LCs bonnet ...) where is the EGR valve in relation to the main pic with the intercooler off??

It's on the RHS (When facing the engine)
You can see it with the bits still in place, up against the firewall.



Sorry - could not find how to circle something in PB :mrgreen:
Good job.... you free next weekend to do mine? :twisted:
So the leak is back :(
It's pretty clear now that it is leaking from the hose connecting the intercooler to the throttle body. It's not a lot, more a small drip of oil from the intake air which pools at the bottom of the hose.
I want to undo it all and smear some black gasket maker around the inside of the hose and then tighten it up again. any reason I should not do this?

When I first bought it I asked about the leak and they said they tightened it up. When I undid it, it was obvious it had been pretty tight. Will over tightening a hose / hosepipe clamp ruin the hose? Guess I am asking, should I bother with the gasket or just buy a new one?

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Overtightening and heat will deform it. Probably best to get a new one from Ian.

Hi All

Just back from a pleasant week in Stockton/ Bob- Murph land. 1300 miles of it with the gang. Three little people in the back of a LC for that miles in a week was, eh, challenging.

Anyway, I have a small leak at the EGR valve too so this is interesting. It's just enough to have a tiny film of oil on the body so worth investigating someday now that I know what it is! Thanks Crispin. :clap:
I would check the pipe between the intercooler and the throttle body first NC. It is definitely that that is now leaking. Like you say though, it's a film on the heat exchanger / EGG body. A replacement is about to be ordered for me
I did check and the rear most of the Jubilee clips was a few turns looser than I'd expect. Duly tightened and wiped clean. Watch this space. :pray:
Look back at Crispin's side-on view of the engine with the 'I'm an EGR valve' balloon. The leak was on the body of the valve here, mainly in the area where the rubber air pipe connection is. I say leak, but it is all relative. Mine had just enough oil on it to collect dust and spread a bit. No drips that I could see. Crispin's may have been more significant than that.
My main leak was the black pipe between the intercooler and the throttle body / EGR valve. I replaced it yesterday and so far, all is good. It was now leaking to a point where I could hear it hiss in the cab as well as blowing oil against the underside of the bonnet. :o
Interesting that that is a D4D. I was chatting to someone else about it a while back and we were wondering if the ECU would get upset at the fact that the EGR valve is not responding.
:thumbup: Thankfully tightening the clips seems to have done the trick. I'll be leaving well enough alone for now. Running nicely and everything works.
I thought by blocking it off, the emissions go up, and the MOT folk will have a frothy?