IMS Failure - Need Advice

[Tim1137]

Originally Posted by seningen

All depends on what you decide to do and what damage was done.

Goto Pelican and add up the parts you are going to need.
Assume bent valves, IMSR, probably have to source a used IMS Tube.
head gasket, engine seals kit, fluids.

Then you have a lot of WIAIT costs.

It adds up quick. But you should be able to do it for 7-10K depending on labor and WIAIT costs -- however upon
teardown -- you might find the damage was catastrophic.

A 2.5K engine might be fine -- or it might be a nightmare.
Check the leak down, IMSR, and replace the WP at a minimum.

Mike

Sorry for my ignorance, but what is WIAIT, and what is an IMS Tube?

[seningen]

Originally Posted by Tim1137

Sorry for my ignorance, but what is WIAIT, and what is an IMS Tube?

WIAIT is a dreaded curse which is
While I Am In There
which translates to an empty wallet :-)

I don't have any pictures handy at the moment -- they reside on another computer
so you'll have to bear with me textually.

IMS Tube: InterMediate Shaft Tube.
It is the Tube that runs along the bottom of the engine.
The front side is connected to the Crankshaft by a chain, (on a boxster)
a chain in the front drives the right most cylinder head camshafts
the rear drives the left most cylinder head camshafts.
it rides on the IMS Bearing on the front which is held in place
by a bolt (which can fail) to a flange on the front of the engine.

The rear rides in a cavity in the block and also drives the oil pump.

When the IMS starts to lose the support on the front of the engine
by either having the bolt sheer or the bearings fail
it will still spin (to a point) damaging the far end of the IMS tube.

We were able to rebuild 2 IMS failures by replacing the tube (and a whole lot more stuff) -- But it is hit or miss depending on the damage done.

Last night my mechanic pulled a bearing from a 2001 Base 91K mile Tip.
It had an RMS leak -- but otherwise ran flawlessly.

If you look closely -- you can see the metal filings around the seal of this IMS Bearing assembly. It was just a matter of time before it failed.




There were no indications in the oil filter either.

After he finishes some other work -- I'll have him disassemble the bearing race and see what it looks like inside


Mike

[thstone]

Originally Posted by Tim1137

Sorry for my ignorance, but what is WIAIT, and what is an IMS Tube?

WIAIT - While I Am In There - meaning that there are always a number of components that may not need replacement but its a good idea to do it as long as you have the engine apart. Things like cam chain guides, oil pump, etc.