Call me j 75: This is a good point but not all agree.I read somewhere you could resurface or grind the valves during the headgasket repair without problems, but there are a lot of opinions out there that say it places too much pressure on the bottom end as you mention. The machine shop technician that I took my heads to to resurface(flatten) didn't want to make ours an oil burner so since it wasn't burning oil to begin with we didn't touch the valves; just replaced the intake valve seals. When you say your bottom end is going, is it knowcking, burning oil with blue smoke, loss of compression, or what exactly and after how many miles did this happen. You must have ground the valves am I correct?

 

I bought the heads off ebay and it was described as "reworked" heads and the valves were ground and heads resurfaced. I had to replace one cam due to someone breaking a chunk out of it.

After the rebuild I ran it about 100 miles and changed the oil. Then ran it maybe another 200 and took it on a trip about 3 hours away on the interstate and I noticed it knocking at startup in the cold morning. I figured it was due to the 10-40 oil so I just changed out the oil and filter again this morning and the knock at startup is still there. After the oil pumps up it gets quiet. Then at cruising speeds you can tell there is a knock there...not real bad but its noticeable. There is no smoke as of yet. The lower end had 220,000 miles on it before the head gasket blew so in reality I should have rebuilt the bottom end while I had the motor out.

 

Wonder if anyone can explain the knock? Interesting that it goes away. I'm wondering if the knock could have been there all along. Sometimes I think I'm hearing mystery noises too. One can't be too careful. Let us know what happens. It all adds up to experience. Is yours a daily driver. 220K isn't bad, a long way from 300K.

 

Yeh its a daily driver. I'm a guy that notices every knock and noise and every little gauge movement and there was no knock present before the rebuild. It seems to have fine power even in the upper rpms. Me and strap22 talked about it and it sounded like it was a predetonation knock so I reset my distributor and still didn't help. So I ordered a Toyota oil filter from him and put in 10-30 oil and still didn't help. Dunno...guess I'll find out when it finally goes! When she does it will get a nice fresh V8 transplant

 

Thanks: As you know by now I'm just about whre you're at having done all the hard work myself to the tune of $350 and giving up my weekends, But what real choice did I have with a $6500 bill to replace the engine from a mechnic in Bend. I didn't mind doing the repair as I've never had any serious problems with any of the many Toyota engines we've pushed past 250K until this 3.0; funny thing if the RTV sealant leak under the top idler pulley hadn't disappeared don't think it would have ever overheated. I now believe the head gaskets were fine, maybe a slight external leak. Will never know for sure. I thought the other day when I was outside listening to the engine warm up I heard a similar small knock, it too went away. My daughter will be making another 400 mile round trip in the ride and when she's back I'll listen to it some more for the mystery knock. Strap 22 seems to have an ide. I can rev the hell out of this and it seems to run fine, oil is clean. I'm curious if this is the same noise you hear. does it do it every time on startup. I only heard it once on this and that is in 1200 miles since top end rebuild. Go figure. Believe the timing is dead on, not sure about TPS yet. One code 71 engine check light is all I have to go on, I do have a "false" KS wire rigged up as per Mudcat's post. Let me know how your engine runs and what you find the knock to be!

 

I rewmembered to replace my KS wire while I had it apart because my old one was pretty frayed. When I did a rebuild I got the TPS code and 71 but mine went away and has never came back. I can rev mine too and no noise but under load going down the road it seems to knock rhythmically with the motor. Not loud..but noticeable. It could be the same knock you are experiencing. I had my brother in law listen to it and he said it sounded exactly like a wristpin. I don't know...I'll keep ya informed though.

 

Noisy fuel injectors are what I hear. I now want to learn more about valve knock and predetonation knock. If the ride goes 400 miles round trip and has already logged 1200 miles by me since the repair, I don't think it's anything serious. What's a wrist-pin knock.My valves were shimmed and all are within tolerance. I'm thinking this is timing related. Also wonder about the cold start injector and whether it could be related to that. The noise I hear when traveling I have traced to my "noted for being noisy fuel injectors" and my thinking goes like this, if it was something serious,why does it run so well?

Good luck with your mystery knock. Keep me posted.

 

hey well I did the top end rebuild on my runner a few months ago, and ya it was a chore, especially the exhaust. But now my runner runs perfectly now. Ya the 3.0 is a pain to work on, but the newer 3.4 is even worse! Doing the rebuild will make your truck laast longer without spending the big bucks, but if you have the dough then go right ahead. There might already be one, but I think someone should make a full complete writup of rebuilding this stinkin 3.0

 

Well first off when you here TRUE engine knock as in detonation or pre-ignition you wont hear it at idle...there is not enough load on the engine to cause enough heat...maybe just off it but that is only in extreme cases where you have your timing WAY TO HIGH or no fuel going in, which again is very extreme.

You may be confusing this for valve/lifter tick? Which is similar to injector ticking...but only happens as the engine warms up (normaly)...
What oil you guys using? and whats your air temp right now....

 

We had a cold snap here where the air temp was in the 30's in the morning F that is maybe even 28 F or so. I'm happy for the rebuild (head gasket repair) and the engine seems to run out fine.It wants to run at about 1500 rpms with it colder outside until it reaches warm up. Weather has warmed into the 50's now with mthe rain we're getting, I'll see what's up hen my daughter gets back for Christmas; i.e. I'll moniter any noise on startup and note the rpm.

I think everything is fine just a bit nervous after the headgasket repair. I think a guy starts imagining things after a serious repair like headgasket on the 3.0 ;however when the vehicle runs down the road fine, starts fine, has great oil pressure, runs just this side of middle on the water temp guage, no loss of coolant or oil, I think no worries mate, she be right as the Aussies say or relax and have a homebrew as the homebrewers are fond of saying.

Just needed a llittle reassurance that all is well for a do it yourselfer. After all it's a Toyota; just keep oil in them they seem to run forever.

 

well that sounds 100% normal to me right now!
dont worry about it!