I know its very common for heads needing to be rebuilt around 160k - 200k miles. My first 4Runner needed a valve job bad at 170k and my second 4Runner's was done at 169k (didn't show symptoms like my first one but I was doing a HG so I had a machine shop look at the heads and he said all the valves were leaking, so I got them rebuilt).

So my question, and the reason for this post, is to find out how long you can expect the engine's bottom end (the end Im NOT familiar with) to last. How long until piston rings or crankshaft bearings wear out, or until the block needs honing or reboring.

If anyone has seen signs of these things happening to their bottom end, I'd like to know how many miles the engine had.

 

My bottom end started knocking after a fresh rebuild on the heads....it had 220,000 on the motor if that helps

 

My last truck approached 300K miles but was stolen before I could break that threshold. It was at 297K, no oil burning issues.

Frank

 

Mine had 106k on the motor when the HG went. I tore the bottom end apart because I had no cross hatch left. The bearings, rods, journals, crank -- everything looked beautiful. I do not have to have the crank turned or have the decks on either the heads or block milled. I am having the heads redone and it is having to go .040" over on the cylinders. I had an odd taper in the bores(we might have been able to go .020" over but I didn't feel like getting it wrong.

Kat

 

The 3.0 has one of the most robust bottom ends of the 'Yota V-6 engines. Baby got back!

As long as it hasn't been oil-starved, it should be good for a long time.

EDIT: I will preface that with the fact that if you've had coolant in your oil as a result of HG failure, you might want to get an oil analysis done. Coolant can cause catastrophic bearing failure if it goes on too long.

 

276500 and counting baby!

 

Man, that sucks. Did you tear it all apart and do a full rebuild on the bottom end then?

I found a sweet 92 4runner with a blown headgasket that the kid is selling for $1050. I might get it but that is my worst nightmare, that I do the whole top end and after I get it back together it developes a problem in the bottom end. All that work would be a waist and would have to be redone.

 

EDIT: I will preface that with the fact that if you've had coolant in your oil as a result of HG failure, you might want to get an oil analysis done. Coolant can cause catastrophic bearing failure if it goes on too long.[/COLOR][/QUOTE]

Get an oil analysis done before or after you change the bad oil? I did the headgasket on my current 4runner and it has fresh oil now. How would an oil analysis at this point tell me anything?

 

I had the whole motor out..just got some rebuilt heads and did the top end. Ran it for about 500 miles, changed the oil, then ran it for another 1,000 miles or so...and took it on a 3 hour trip and the next morning I started it up and I heard it knock. I was not happy..

 

Get an oil analysis done before or after you change the bad oil? I did the headgasket on my current 4runner and it has fresh oil now. How would an oil analysis at this point tell me anything?[/quote]

Well, no. Post oil change an analysis won't tell you anything.

 

299k and still screaming with no HG done.