I bought a used 94 RR LWB 4.2, the RR was a trade in at my Audi dealerrship, its is in fantastic shape, everything works well worth keeping running, just turned 100K. OK, so here is my dilema, before the original owners traded the RR in, they had the head gaskets replaced, less than 3k miles ago. Right after I bought the car, the water pump started to leak, so I replaced that, and all was good, then I noticed I was loosing coolant, and burning it out my tail pipe, so I did a pressure test, and pulled plkugs and sure enough cyl #3 is the culprit.

Knowing that these engines are touchy with overheating and dropping cyl linners, should I pull the heads do the head gaskets again, or just buy a used engine.

Any advice would be appriciated

BTW, I found a couple of used engines, one has 89k, the other just over 100k, both are under $1,500.00, if I did buy a used engine I would replace the head gaskets right away.

 

What's that expression about "the devil you know, vs. the one you don't"?...or something like that. If your engine is running well now, I would pull the heads, and inspect CAREFULLY all of the threaded holes in the block that the stretch bolts use to clamp down the heads. Many shops--- not especially informed--- don't realize that these bolts are "one use only" fasteners. They are indexed (as opposed to simply torqued to a ft/lb value). The procedure is bringing them all to 15 ft. lbs in the proper sequence. Then you use "white-out" and paint a vertical line on each bolt head. Then you repeat the sequence and index them all 90 degrees (1/4 turn). And then ---you repeat the sequence and index them another 90 degrees. This is necessary to achieve the proper clamping force on the composite head gasket.

As you can see, if there are any "pulled threads" in the block, you will not be able to achieve the proper force, and you WILL lose another head gasket. Sometimes a damaged block can be repaired with a heli-coil insert, but only if a couple of holes are affected, and not when those surrounding a given cylinder all need heli-coils.

So-- when you pull the heads, and if you see a cylinder sleeve or two that has dropped below the deck surface--only then would I go looking for a used engine. And this is because you now have to.

read my tech info pages at the site. This gives you a good primer on what to look for.

I have the head gasket kit that includes all of the head bolts at a very good price on the site. Let me know how I can help.

regards,
Geoman

www.eurotekapg.com

 

Thank you!

The engine, starts and runs perfectly smooth, tons of power.

So I will pull the heads and inspect them this weekend.

Thank you again for your help, I will post on Monday as to what I find