head replacement

[97catera18]

what would be easier to do? replacing a few bent valves and the cylinder heads..or just changing the whole motor? this is for a 97 cat. I have a motor with high miles that runs great...And I have a motor with really low miles that the timing belt went on. Could I Use the parts from my cat that has high miles on the motor with low miles?? Thanks for the help..!!
-E

[Marks DTM Calib]

I would say yes.....I have changed a few heads (following cambelt failure wen peopel dont follow the 40K 4 year rule!)

It normlay costs me about £220 all in with a new timing belt...

I would take the good heads and strip them, clean the valves up (put them in a drill and use some wet and dry with some soapy water, dont touch the seats), fit new stem seals and clean the heads up well before re-build (note, paint stripped is brilliant at removing carbon and oil staining).

You need to use the T vents off the replacement engine (two per head, torx headed) as they must match the oil pump (it changed in around 98 to a higher pressure variant).

Also worth cleaning the followers, see here for how to:

Cleaning and checking a follower

That way you are fitting an excellent set of heads.....to a known good block...

Re-seal the oil cooler plate whilst there and use the same sealent around the stat housing (or fit the later modified setup)

[frank moran]

Originally Posted by Marks DTM Calib

I would say yes.....I have changed a few heads (following cambelt failure wen peopel dont follow the 40K 4 year rule!)

It normlay costs me about £220 all in with a new timing belt...

I would take the good heads and strip them, clean the valves up (put them in a drill and use some wet and dry with some soapy water, dont touch the seats), fit new stem seals and clean the heads up well before re-build (note, paint stripped is brilliant at removing carbon and oil staining).

You need to use the T vents off the replacement engine (two per head, torx headed) as they must match the oil pump (it changed in around 98 to a higher pressure variant).

Also worth cleaning the followers, see here for how to:

Cleaning and checking a follower

That way you are fitting an excellent set of heads.....to a known good block...

Re-seal the oil cooler plate whilst there and use the same sealent around the stat housing (or fit the later modified setup)

Mark, good information. Have you experienced any lifter failure as a result of belt failure and piston valve contact? I am chasing a noise and I'm hearing some valve lifter noise that may be the culprit??? Today I am putting a tech 2 to look at the KS's just to eliminate spark knock...thanks.

[Marks DTM Calib]

I have yes.....the test above shows any failures up nicely.....

[Marks DTM Calib]

Ok bit more of a detailed reply for you (was in a rush last night).

If there is any detectable knock then the ECU automaticaly retards the timing by 20deg+ and throws a fault code....so unlikely to be spark knock...

At high mileage and with poor servicing the lifters can get tappy (as they can on any engine)...using the above method to clean them out normaly fixes this (the colour of the oil that comes out can be quite shocking and you can feel the grit in it!).

Also check the exhaust manifolds for ticking, earlier power plants used a pretty naff composite gasket setup which deteriorates with time, the replacements are a multilayer metal affair which is MUCH better...

Its a case of use a listening stick or length of tube to pin point the noise.....

[frank moran]

Originally Posted by Marks DTM Calib

Ok bit more of a detailed reply for you (was in a rush last night).

If there is any detectable knock then the ECU automaticaly retards the timing by 20deg+ and throws a fault code....so unlikely to be spark knock...

At high mileage and with poor servicing the lifters can get tappy (as they can on any engine)...using the above method to clean them out normaly fixes this (the colour of the oil that comes out can be quite shocking and you can feel the grit in it!).

Also check the exhaust manifolds for ticking, earlier power plants used a pretty naff composite gasket setup which deteriorates with time, the replacements are a multilayer metal affair which is MUCH better...

Its a case of use a listening stick or length of tube to pin point the noise.....

thanks mark, it's not spark knock, KS doing their job. I'm going to have to look under it real well and see if anything is loose, used the stethoscope method but I can only get the noise on light acceleration, possibly the engine torgque is causing an interferencce drives me nuts...