is my m42 Done for?

[rob_e30]

You can do this job with the engine in the car.  The biggest challenge is getting the crank bolt off... it's a 22mm socket and you need to lock the flywheel or find a way to secure the crank pulley.  I welded a piece of steel square stock to an old crank pulley, bolt that in place of the stock one, and go to town.

Plan on replacing all of your timing guides, chain and tensioner.  It's tough to see in your pictures, but it looks like your cam gears may have gotten very pointy.  They are not supposed to be and would likely benefit from being replaced too.

Do a compression test to check the status of your valves.  If it fails that, you will likely need a valve job.  All of it is do-able but you need to look at the rest of the car to determine if it's worth it.

[Letsplayskatch]

Do a compression test to check the status of your valves.  

Or Piston rings...

[fiftytakedowns]

Lot's of Good info, Thanks!  Looks like Ill be pickin up a compression tester.

[VegasKyle]

Lot's of Good info, Thanks!  Looks like Ill be pickin up a compression tester.

Don't buy one unless you think you'll use it more thank just this once.  Most auto parts stores will let you borrow one.  Just put down a deposit for what its worth and you'll get it back when you return it.

[fiftytakedowns]

I was planning on gettin one from a friend! Thanks for lookin out though, I appreciate it!

[fiftytakedowns]

I just picked up a spare m42 long block in great shape, too bad it has 0 compression in two cylinders. LOL Im hoping to use parts in case that there is no internal damage on my m42.

or part it out to buy a spare lol

Morgan

[tom d]

i'm sure you won't find any damage to your M42. as stated above, the part you found is from the timing chain components. i rebuilt a M42 with 183K miles on the clock. the engine internally was great. the timing parts were a mess. the rails had self destructed and where scattered about, but the car still ran.

you will need to replace the timing rails. the cams gears look okay, and i'm willing to bet the chain is also.

[VegasKyle]

Like I said before we seem to be having a similar problem or at least similar symptoms.  I pulled and replaced all my timing components last weekend and this is what I found.  I knew my guides were bad because of pieces of plastic in the oil pan.  I also suspected the idler sprocket could be bad.  In fact it seemed to be in perfect shape but I replaced it anyway.  The main culprit was the chain rail (#6 in the real oem diagram), a huge piece of it broke off and caused the lower guide to break as well.



The piece you found is from the same rail.  I'd imagine the same thing happen to you.  I know of at least one other case where this same guide failed but it got caught in the crank sprocket and caused the chain to jump time and bend all the valves.

If you are looking for the most cost effective route I'd pull apart the spare motor you have and see what can be used.  It's hard to see from your pics if the cam sprockets have pointy teeth or not.  Mine were in great shape so I decided not to replace them or the crank sprocket.  I could have left the idler alone too but I already bought one off ebay.  At a minimum you are going to need 4 new guides.  But if you go through all the trouble of pulling everything apart I think its worth it to spend the extra couple hundred dollars and do the chain, tensioner, and cam gears too.

[fiftytakedowns]

here is the spare engine thst I just pulled apart.  Ill get my car towed here, and start tearing it apart to see what is going on with that engine. but it looks like this engine only had a blown headgasket, and a broken rail just as the one above you showed.

I wonder what would be the cheapest way to do an R&R given I have two engines.
Also,  This engine was supposedly had no compression in two cyls, and when I popped off the head, I found coolant in two cyls... (headgasket and not rings?)