Q45: Replace KS without removing water/coolant hose?

[PachoC]

Is it possible to replace the KS withouth having to remove/replace the "Y" shapped water hose connecting both banks? Is there enough room to properly torque them down? Or is it a must to remove the hose? ....I know, I should replace all the hoses at the same time....but $$$ is a factor now.....

[maxnix]

Hoses are relatively cheap compared to time or labor.

Replace them. I bet they are quite brittle and deteriorating on the inside.
Modified by maxnix at 4:54 PM 11/18/2007

[tt300z]

with the right tools i didnt have to take it off.....or cut the rubber tube....make sure you make am tight ... i have done it 1 year ago and everything is still good... now if you can't get your hand in there then go ahead and cut the rubber hose.....do not remove the y looking tube NO NEED TO

[PachoC]

Brian, you are absolutely right. I can just replace the water hoses (not the whole Under Plenum $$$ kit).

TT, tks for the tip about not removing the tube.

[mxr662]

I replaced the hoses however it does look possible

[3Q Jay]

i know for a fact that it *can* be done, becuase i have.i did remove the lower plenum runners, however.

[Q45tech]

We try to save members future agony and melted engines by suggesting processes which in the long run will save them money especially since the life of the under plenum hoses is so short [about 6-7-8 years or 70-80,000 miles].

I have replaced these coolant hoses 3 times so far in 17.8 years

The knock sensors seem to last 12-14 years depending on local summer ambients. OF COURSE a single over heat leads to immediate failure of KS. Part of the system design to fail so you pull the plenum after overheats and R&R.

The plastic on KS has a low cracking temperature again by design so that when the cylinder head over heats it fails before the cylinder head fails and reduces the maximum WOT ignition advance.

KS are cheaper than cylinderheads and engines.

Of course owners are capable of destroying both fast if they are insensitive to the needs of the engine to stay coolish.

[PachoC]

Tks for the pictures! Now I have a clear idea of what needs to be done in order to replace the KS. Based on all the feedback, it makes sense to replace the coolant hoses, too... Has anybody experienced just a harness failure (and not the KS)? I measured the resistance one day and one was open and the other was ok. A few days latter both were ok. Yesterday, both were open... Could it be just the harness? Or is this common beahaviour for dead or almost dead KS that need to be replaced?

[Q45tech]

Never really seen many harness failures just corrosion on connectors.........we change then because it is easier and cheaper than cleaning them and warranting the system for 12/12k.

There are always hairline cracks or worse on every 5 year old Q45 KS due to rise in underplemum heat after shutdown..............the shorter cooler your summer the longer they last.

[grabberman]

When you put everything back together, be sure NOT to bump the starter. Hand crank the camshaft nut 4 complete revolutions (4 Stroke)CLOCKWISE. If something falls into open runners of intake, like me, you will not have to remove cylinder head to fix valve.

[dabbas]

hey all, i'm replacing a water hose on a 1990 q45 and would like some advice on how to access the hose which is directly under the intake manifold. it's the black hose in the 2nd pic in the 5th post, it's about 3" long with the 2 clamps. any help would be appreciated, walkthroughs, advice etc. in accessing the hose.

[maxnix]

hey all, i'm replacing a water hose on a 1990 q45

Just one? Do you like repeat labor?

Replace them all, including KS and its harness.

How are your timing chain guides?