OM602 glow plug DIY
 

'87 190D with 2.5 turbo has a glow plug issue I need to resolve. Is this one of the models where the glow plugs want to stick and break off into the head? Does the intake manifold have to come off and if so does it require a new gasket? Is there a good tutorial to reference?

no. other than needing to remove the intake manifold for ease of removal, the GP's are simple on this vehicle.

I did my 92 300D 2.5 (602) without taking the intake off, take your time, its not easy.

The OM602 and OM603 have a different head design than the notorious OM606. The glow plugs are about 1/2 as long as the OM606 plugs and normally won't be stuck.

I've done mine (and helped vstech with his) OM603 powered 300TDs. In both cases a couple plugs were stubborn and had to be worked back and forth gently a little to get them out.

As long as you are not applying gorilla torque you should be ok.

I have heard of people not removing the IM but it requires serious contortion to be able to reach around everything to get to the GPs.

The hardest part of IM removal is getting to some of the 6mm Allen head bolts. Some do not have a clear path of approach for most Allen key tools. Try to use only a flat end tool (not a ball end tool) to break torque. Once torque is broken then you can switch to a ball end.

I would also work with a helper and have them stand by with a claw tool to grab the bolt as it is coming free. It is a major pain to retrieve the bolt if you happen to drop it.

Once you have all the bolts off and the cross pipe disconnected the manifold just lifts off.

I would as a side project be prepared to clean the gunk out of the IM and bypass the EGR if you can get away with it in your location (depends on how strict your vehicle inspections are).

The other pitfall is sometimes the electrical nuts are stripped on the back of the GP and it can be a real pain to get those free. The nuts are *supposed* to be captive on the wire lugs but I have encountered broken retainers before so be prepared if the nut seems loose.

When reinstalling the plugs coat the threads with anti seize. Be gentle on the electrical nuts, they only need to be snug, otherwise you risk breaking the element inside. Also pay attention to the angle of each lug, if they are rotated too far from where they are supposed to be they can short out to the manifold and blow the fuse. Best to check this after reinstalling the manifold to be sure none are shorted.

And yes you will need to renew the manifold and cross pipe gaskets. They are not very expensive and readily available from the forum sponsor.

Speaking of parts, I would only use Beru or Bosch glow plugs.

Thanks for the guidance!

Am I missing something or does Pelican no longer offer glow plugs for this model?

I've done an EGR delete on an OM617. Is there a good reference thread for an OM602?

Be prepared to install a pressure-activated wastegate if you do... messing with the EGR on a 602 turbo will open the wastegate.

I've read that to be the case with the 2.5's in the '90-'93 124's but I didn't think that was the case for the '87 W201's with a 2.5?

Still looking for guidance on an EGR delete.

If it's like the 87 603, it is easy enough to unplug and disable with out physically removing it. Not having looked at your model, the 603 has 2 vacuum lines, one running to the egr valve and one running to valve on the turbo that is also related to egr. If your sound like this, then remove and plug and see how she roles. If you've lost power, then put it back.

If you look at the picture below, I actually have a line running from one to the other to give it the appearance of doing something really really important.

http://i.imgur.com/egC4bRs.jpg