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Hi All,
I have myself a little dilemma and am in search of some answers and advice.
A little info about the truck:
1987 Base Model 4x4
22R @ 137,000mi on the clock
5spd Manual
As stated in title I have a knock at roughly 2k rpm that disappears if I pull the vacuum advance lines off. You can hear the knock very plainly in this video:
After checking a plethora of things I finally pulled the valve cover and found that the Drivers Side Chain Guide is Gone. Could this be the cause of the knock or is it something else. Passenger Side Guide Remains of Drivers Side Guide
This is my daily so I want it in good shape and mechanically sound, I plan on doing the timing chain, guides, oil pump, water pump, and pulling the pan to remove debris; unless deeper issues are discovered.
Planning on going through LC Engineering for chain kit and pumps, any other good recommendations for parts?
Also should I look at doing my head gasket while I'm this far into the engine?
I just want to make sure this engine is reliable and set to venture off to wherever I take it.
I strongly suggest you pull out the motor. If you don't you'll think ahh this ain't so bad..
If you do you'll be like WHOA this was so much easier!
head gasket- yes
Rings- yes
Rod and main bearings - yes
The rest depends on wear and how deep your pocket book is.
Get a remflex gasket for the exhaust manifold.
You can do this!
I'm 68 and literally dying from cancer and just pulled the motor out of my daughters 87 4runner sr5 5spd. I could have done it in a weekend. But had to come to MD Anderson in Houston... so I'll finish out when I get home
Unless I'm misunderstanding you, why replace rings, rods, and main bearings?
At 137k miles with regular maintenance, I feel this engine is plenty healthy to not require that deep of a dive.
I believe the knock is just chain slap, if it was crank or other, it would be consistent and pulling vacuum advance would not make it go away.
My condolences regarding your cancer diagnosis, my mother passed at 50 with pancreatic cancer.
There is no need to replace piston rings, or engine bearings unless you have a good reason to.
The proper way to replace the timing chain has you removing both the head and oil pan, so I would definately recommend replacing the head gasket while you are replacing the timing chain.
About maybe 12 or 13 years ago I did my timing chain, only to find that I still had a knock at very narrow RPM range. Mine turned out to be rod knock from worn out rod bearings. I had to drop front diff, drop the oil pan after having just been in there to do the timing chain.
I can't really tell from your video, so I'm not really telling you that you have rod knock. But I will say if you go so far as to drop the oil pan, take off the crank bearing caps one at a time and look at the bearings, if they are worn out, that's a good time to replace them.
To drop the oil pan with the engine in place, you have to remove the front diff, which is a lot of work to do laying on your back. I can see an argument where pulling the engine is almost just as easy, and you are standing up the whole time.
Ok Dixon,
Here's my anecdotes re knocks and valve timing issues..I wouldn't presume to give advice, cuz I'm old school shade tree tech.( mine's an '89 basic dr 2wd 5spd 22RE, just turned over 200,000 miles last month). I heard the slack timing chain at startup rattle after I bought the vehicle. Checked this forum. Read all about it. Bought parts and took it apart. Plastic timing guides failure; two nice grooves on the driver's side of the aluminum case. Looked like done on a milling machine. Bought more parts. Read about how to do it not messing with the head gasket or pan gasket. Thought that's the way to go. Worked fine for me. Was careful and probably lucky too. My reasoning: can't get a better gaskets than factory and can't do a better installation than factory. Plastic debris is probably on the bottom in the muck and not going to cause any problem which I can't say about me on the floor looking up and installing a pan gasket, or trying to clean and inspect the top end surfaces and attempt to install a new gasket. So, timing chain issue taken care of 50,000 miles ago. Runs good; expect it will outlast me.
Knocks. Mine has one very audible connecting rod bearing knock for two or three or four rotations after start until the oil film is established. 50 years ago I would have been all worried about it and pulling the engine out for teardown. Now just ignore it. Its been that way since I got it and while my bro owned it before that. The engine doesn't worry me a bit. It's all those old coolant hoses that I'm too lazy to mess with.
Let’s do a compression test before anything else just to see if the engine is as healthy as you think. If you do pull it, it’s easy to see what’s in the pan and get a look and plastigauge measurement on the bearings. With the head off you can test with solvent and address any leaking valves and replace valve seals.
10-04-2023, 10:04 PM
Knock at 2k rpm and Timing Chain Replacement
