87-4runner

so true!!! I'm very confident doing this job on my Turbo rigs and the non turbos are soooo much easier to work on...
If someone needs help with this your welcome to call me anytime for a walk thru over the phone.
​​​​​1 580 541 2854

Blueman

Everytime you open up an older engine, there's risk, so the point of inspections are to balance the risk of tearing things open against impending failures.

For example, after having to helicoil two exhaust studs, I'd fully expect that if I pulled the head that might happen again. Trouble is, the last time it happened (threads pulled out) when reinstalling the manifold, not on removal.

I'm all for preventative MX, but firmly don't believe in "Must replace the chain & guides at 100k miles" or "Must rebuilt at TBO". It's all a delicate balance of risk vs. reward.

And it's all a slippery slope of repairs. Water pump leaking? Fix it, but well, while you've gone that far you might as well change the chain&guides. Changing the chain? Well, you might as well pull the head and change the headgasket. Pulling the head? Well, you might as well rebuild the bottom end. Going that far? Well, you might as well just pull the engine and do it all on the bench indoors.

The original goal of this thread was to understand if people felt it was possible to do an inspection of the guides by just pulling the valve cover. Clearly, if guides have failed, then chain work is the next step, but if the guides are in good shape, then that's a separate discussion of when to tear open the engine.

87-4runner

Well said Blueman
another factor is MONEY.
Some folks have a pocket full and can do the whole enchilada, others may have to do things in stages, while others just try to get by...
I changed my timing chain, gears and metal guides because it was a kit...
but I didn't do the water pump or oil pump they were working fine.

wallytoo

iTrader: (1)

when i recently did the timing set and headgasket (2x because of my dumbassness), i did not replace the oil pump or water pump. i replaced the timing/gasket because the gasket had an external leak, and thus i had to do it. when i pulled the head gasket the first time, i discovered that the driver side guide had a missing piece around the upper guide bolt, and so i replaced the set in addition to the gasket. then did it again two weeks later. weeeee.

howsomevers, about 1 month later, the front main seal began leaking (i admit that i did not change it during the two gasket/timing changes), so i pulled that and replaced it. but not the pump.

for me, even though i can afford it, money is ALWAYS an issue. pay attention to the small stuff, so it doesn't turn into large stuff.

Jimkola

You are correct, I misread a post

Co_94_PU

iTrader: (-1)

This kind of went off topic "can I.."

Yes you can get a good sense of the chain guides health by just pulling the valve cover (ho deep if any are the grooves, AR the hold downs in tact (you can check these with the mark one eye ball and a long reaching tool).

To check the chain you need to measure 16(?) Links and you're not going to do this with the timing cover in place.

Blueman

Thanks, Co_, that was the question. These days it's nearly impossible to ask a question and not have the topic be derailed.

This particular truck sees only about 1,000 miles a year and isn't a required DD so if the chain&guides are still within tolerances, it's of questionable value to tear it open given the cost, labor, and risk of creating other issues.