Hi all,

When I got my car I found that the air intake temperature sensor just before the EGR had been damaged and the O ring wasn't sealing properly - the 2 plastic lugs were damaged.

I was just wondering what the intake temperature sensor does, I know on on petrol powered cars the intake temp on a turbo powered car is key to avoid detonation.

Will there be any issues if I were to unplug the intake sensor - I only ask as the port the sensor is using would be perfect for the water/meth injection system I was looking to install soonish.

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UK spec Mercedes W210 E300 Turbodiesel wagon - OM606.962 with 722.6 transmission - rust free!

Don't know what kind of car you are referring to but if it is one with a computer you will, in all likelyhood, get a check engine light with it unplugged.

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Jim

Its the one in the signature - will perhaps unplug it and see! Wasn't sure what other systems it might be connected to though, I know if you remove the vac line from the EGR the engine drops the boost. I am guessing that it might just work in conjunction with the MAF for the most efficient fueling though.

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UK spec Mercedes W210 E300 Turbodiesel wagon - OM606.962 with 722.6 transmission - rust free!

The sensor you are referring to is a combination MAF and IAT sensor.

Unplugging it will give you a code and limp mode. The car has a traditional IP, but the computer tries to do what it can using the MAF and IAT data to influence fueling, the EGR, and the waste gate. The goals are to meet fuel economy and emissions regulations, and protect the engine.

It uses the MAF data to confirm the EGR is working, it's pretty crude by today's standards but basically it wants to see a corresponding drop in the MAF when the EGR is actuated. This was to satisfy the first generation mandates that the emissions system had to be able to check itself.

The MAF housing is plastic, you should be able to easily make a tap for your injection system. But I would definitely do it downstream of the sensor.

Modern CDI engines can do so much more with the injection events than a traditional IP. Not only is the length of the event controlled with microsecond timing, but there are multiple injections performed within the injection interval each time it comes around for that cylinder.

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The OM 642/722.9 powered family
Still going strong
2014 ML350 Bluetec (wife's DD)
2013 E350 Bluetec (my DD)

both my kids cars went to junkyard in 2023
2008 ML320 CDI (Older son’s DD) fatal transmission failure, water soaked/fried rear SAM, numerous other issues, just too far gone to save (165k miles)
2008 E320 Bluetec (Younger son's DD) injector failed open and diluted oil with diesel, spun main bearings (240k miles)

1998 E300DT sold to TimFreeh
1987 300TD sold to vstech

Thanks for that, I had a feeling that it was a combination of both sensors, with regards to the water/meth injection I will be wanting to add it just before the inlet manifold and after the intercooler - I don't want to inject it pre turbo.

I am guessing I am going to have to take the pipe off again from below the inlet manifold - this is the most frustrating pipe I have come across so far as its held in with 1 bolt from the underneath but has to go through a bracket and inlet manifold! A quick tip for anyone reading this post with regards to inlet manifold reassembly is to undo the hose from the intercooler which will allow for the pipe to move easier into the bottom of the inlet manifold.

I guess I will need to take that pipe out again to drill a hole (don't really want metal shavings to go into the inlet!)

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UK spec Mercedes W210 E300 Turbodiesel wagon - OM606.962 with 722.6 transmission - rust free!