Valve Clearance on High Mileage 3.4L?

[RC57]

Anyone ever check their valve clearance at 180k miles or so? I recently bought a 99 with 167k miles on the clock and there's no record of the valves being checked. Waiting for them to get noisy is risky, as I've had shim under bucket valves get _tighter_ as they wear (valve seat and face wear vs cam and bucket wear). Perfectly quiet with zero clearance on the exhaust valves (Yamaha, not Toyota). Anyone have some actual clearance numbers (not specifications)?

There's a receipt showing the valve cover gaskets were replaced at the dealer at 160k miles to fix a leak. No mention of checking the valve clearance, $50 for gaskets + $450 labor.

I checked my 3.0L Avalon at 90k miles and all valves were in spec. Pretty amazing! I might check tham again around 250k.

-RC

 

[brian2sun]

I know this doesn't answer your question, but I think it's still relevant. I'm convinced that shimming valves is just not worth the price on the 3.4 after say 175K or so. A dealer would charge ~$700-1000 to do it because it's not as easy as some V6s like the 3.0. At this point (I'm talking about mine) at 202K, I wouldn't want to spend that kind of cash on my motor and then blow a HG, spin a rod bearing, loose a main seal, have a cylinder die, etc... a few months or even a couple years down the road.

I have no problem just running my 'ol faithful into the ground and then just rebuilding it myself for ~$1000 (or have a reasonable shop do it for ~$1500-2000). That way, I get all new bearings, the valves ground and seated, the block and heads resurfaced, the engine hot tanked, yada yada. I would rather do it all in one shot and run another 2-300K before I have to worry about anything. You take it one piece at a time and it can be an endless battle. Not that it's right for you, but it's definitely the best plan for me.

 

[RC57]

I have no problem adjusting shim style valves. If others have checked their clearance at 200k miles and found them in spec, I won't bother checking them. Considering Toyota recommends checking them now and then I'd think _somebody_ on this forum would have actually done it.

Getting to the rear bank on the 3.0L required removing the manifold. Finessing the feelers in the gap was quite a stretch too, up against the firewall in the center of the car. The 4runner 3.4L looks much more accessible. The only reason I checked the Avalon clearance was due to leaking cover gaskets. Might as well while I'm there. I'm surprised the dealer didn't. Does that mean they've never found a valve out of spec?

I prefer to adjust clearances vs replacing cylinder heads.

-RC

 

[RonMAIDEN]

I can't even recall there being issues with the valve clearances on the 3.4s and there's plenty with over 200-250k on 'em and still no reports of that issue.
I'm not concerned with mine and I'm at 162k and my engine is just as quiet and smooth running as my mom's '99 Limited with 90k miles on it.

 

[brian2sun]

I have no problem adjusting shim style valves. If others have checked their clearance at 200k miles and found them in spec, I won't bother checking them. Considering Toyota recommends checking them now and then I'd think _somebody_ on this forum would have actually done it.

Getting to the rear bank on the 3.0L required removing the manifold. Finessing the feelers in the gap was quite a stretch too, up against the firewall in the center of the car. The 4runner 3.4L looks much more accessible. The only reason I checked the Avalon clearance was due to leaking cover gaskets. Might as well while I'm there. I'm surprised the dealer didn't. Does that mean they've never found a valve out of spec?

I prefer to adjust clearances vs replacing cylinder heads.

-RC

I had the valves adjusted on my old 3.0 and it cost me ~$150 IIRC. When I asked about my 3.4 about a year ago, an indy shop quoted me $700. I called one dealer and was quoted $900. I would do it myself, but the lack of a garage makes it difficult. When I got those quotes I said forget it because I know of a local shop that will do a full rebuild with install and a 3 yr./36K warranty for $1395 + tax or $1999 if they use OEM parts. I won't string it out until I ruin my heads, but I know it's not worth $700 to do it now while my motor still runs good.

 

[Blitzkrieg]

Just for the record, the 3.4 is not a shim under bucket design, it's a shim in retainer design (i.e. the shim sits on top of the valve stem and is retained by the valve spring retainer. You can change the shims without removing the camshafts.

Having done shim jobs on many sportbikes I can tell you from experience doing them on the 3.4 is a comparative piece of cake (especially compared to the zx-12).

1. REMOVE INTAKE AIR CONNECTOR
2. REMOVE CYLINDER HEAD COVERS
3. SET NO.1 CYLINDER TO TDC/COMPRESSION
4. Start checking 'em per the FSM (I use AllDatadiy)

I'm going to check mine at 125K which is 28K away just for peace of mind.

 

[97-4xFunner]

Checked mine around 180k, everything checked ok. No adjust needed.

 

[RC57]

Checked mine around 180k, everything checked ok. No adjust needed.

Now _that_ is useful info. Much better than "I haven't burned a valve yet, so they must be fine."

-RC