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replace cam shaft or whole top of block?


akm
12-05-2004, 09:59 AM
1988 4runner needs new cam shaft and couple rocker arms.
Shop says it needs whole new top of block at $1900 (rounded), or only a cam shaft and 2 rockers at $700... but 2nd choice is not reliable.
Am not a mechanic so not sure of the lingo, but hope the question makes some sense.

The 2 options from the shop were...
1 - r&r camshaft with aftermarket camshaft and 2 rocker arms (would not 'warrantee this option), or
2 - r&r head/gaskets with head gasket set, complete new head/camshaft/rockers/tstat/plugs, etc

'2' sounds like a new engine (top half).
Is there a place I could look at a picture of this engine without buying a manual?
What is the risk in option '1' vs '2'?
Seems like option '1' might involve some subsequent valve adjustment to get things in sync with the new camshaft... and should all the rockers be replaces or only the 2 'bad' ones?
Someone said the coolant needs to come out... is that because the head is being loosened and it would leak out at the head gasket?
Is there a chance the head gasket would need to be replaced with option '1'?
As I said in the beginning, you can guess Im not that knowledgeable...
so any help is appreciated.
Thanks much.

Brian R.
12-05-2004, 01:45 PM
What is the risk in option '1' vs '2'?
Seems like option '1' might involve some subsequent valve adjustment to get things in sync with the new camshaft... and should all the rockers be replaces or only the 2 'bad' ones?
Someone said the coolant needs to come out... is that because the head is being loosened and it would leak out at the head gasket?
Is there a chance the head gasket would need to be replaced with option '1'?

I am not an expert in cam replacement, but IMO, your best bet is to replace the cam and all the rockers. The cam and rockers are worn in together. The risk with option 1 is that if you replace the cam without the rockers, there is a good chance they won't mate and trash your cam lobes. I believe the chances are pretty good that the cam will be trashed. There is alot of load on the cam lobes. Also, once you are in there, there is not alot of extra money involved in replacing all the rocker arms, a little labor and mostly parts.

Unless the head was damaged by whatever trashed your cam, you don't need a new head.

The coolant will have to be drained if you remove the head since you have coolant passages in the head.

The head gasket will have to be replaced if you remove the head. You don't have to remove the head to replace the cam and rockers.

You should make sure they will put in new cam bearings also.

Once you've invested all this money on the top end, don't be afraid to bring the truck back to the shop if the engine is noisy. It is easy for them to shortchange adjusting the valve lash. This is not an issue with all engines, but if it is abnormally noisey, it's bad.

akm
12-05-2004, 02:18 PM
Unless the head was damaged by whatever trashed your cam, you don't need a new head.
You should make sure they will put in new cam bearings also.
Once you've invested all this money on the top end, don't be afraid to bring the truck back to the shop if the engine is noisy. It is easy for them to shortchange adjusting the valve lash. This is not an issue with all engines, but if it is abnormally noisey, it's bad.

Thanks much for the reply.

Well, its my sons car and he doesnt have the money for the new head so Im thinking its kinda between whether to replace the cam shaft and all the rockers or the cam shaft and only the 2 rockers...
and whether he does it here in Seattle or takes it back to his home town (200 miles away) and has a mechanic there (who hes going to call on Monday to get a cost) do it?
The mechanic here is definitely too expensive, so theres got to be another way.

I dont think the head is damaged, there was a lot of clicking going on but the car was still running ok and according to the shop head damage was not necessarily a problem.
What would we look for in the way of head damage?
What you said about replacing ALL the rockers makes sense to me.
I assume whatever else there is like push rods etc would stay?

Were going to get the Chilton manual out of the car today (left it in at the shop, but its sitting outside where he can get to it) so we can take a look at what fits on what... what bone is connected to what bone, and which step follows which step in the DIY process.
So, any suggestions along those lines would help.
Also, if he does it himself it would probably be a good idea to do it here b4 he drives it the 200 miles home and then to take it into his home town mechanic to get valves adjusted etc after driving it there?

Thanks again.

Brian R.
12-05-2004, 04:45 PM
What engine are you talking about?

akm
12-05-2004, 05:29 PM
What engine are you talking about?

Its a 4-cylinder and I think the mod no. is 22re.

forest_grump
12-05-2004, 07:24 PM
Just like doctors...it sometimes pays to get a second opinion where mechanics are concerned....

Not seeing the cam and cam followers first hand I'm unfit to say what problem is ,but all that clicking could just be a case of simple valve adjustment...never hurts to double check even a *so said* reputable shops diagnoises...goodluck

Brian R.
12-05-2004, 09:54 PM
Sure, could just be an adjustment, unless you've seen the bad rocker arms and cam lobe. The mechanic saying they wouldn't guarantee only installing two made me think they knew what they were talking about.

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