Toyota SOHC V6 3.0L question...

« **on:** October 10, 2010, 01:06:31 PM »

Anyone know these things?

I just bought my daughter a second gen. (1993) Toyota 4 Runner 4X4 with the lowly 3.0 V6 (was looking for a 22RE).

It has a knock that their shop said was a rod, but my problem is that it still makes good oil pressure and the sound of the knock is not "rod like" to me....

I have read that these have hydraulic valve lifters on the followers, can these make a buttload of noise?

Anyone that knows these things let me know, it would be very appreciated, I am going to pick it up this afternoon and will start tearing into it later this evening..

Thanks in advanced....

GT

« **Reply #1 on:** October 10, 2010, 01:21:43 PM »

Does the "knock" go away once it is warmed up? or does it stick around?

« **Reply #2 on:** October 10, 2010, 01:25:32 PM »

Quote from: SuperJet on October 10, 2010, 01:21:43 PM

Does the "knock" go away once it is warmed up? or does it stick around?

It never really goes away, but then again, I have not heard it warmed up...She did say it did it coming off the freeway and she drove it straight to the mechanic, then just parked it when he told her it needed an engine, he never pulled it apart and she said it never lost oil pressure and the engine light never came on... $:-\$

I will look into it for a little while tonight, wont be able to give it too much time (worked 14 hours yesterday

) but am more than a little curious.

Thanks!

« **Reply #3 on:** October 10, 2010, 02:45:21 PM »

The 3.0 v6 had an issue with a light knock at the front main bearing. If noise went away when correctly tensioned drive belts were loosened, we would replace the front main bearing shells with the next step smaller(uses select fit shells to "blueprint" the clearance). This only applied to a stock crank. There was a campaign(V06) on headgaskets for this engine. Sometimes the block would end up with excessive erosion around a certain water port in the deck in which case the block would be replaced. This would open up numerous possibilities regarding main and rod bearing clearances. It would help to know the complete history of the engine.

With the high miles some of these engines have now, we have started to see a few major engine failures. A while back I was able to check a rod bearing by simply picking it off the frame rail.......

BTW, valves are operated by shimmed buckets. No hydraulic lifters.

« **Reply #4 on:** October 10, 2010, 04:00:10 PM »

Quote from: Oldsquirt on October 10, 2010, 02:45:21 PM

The 3.0 v6 had an issue with a light knock at the front main bearing. If noise went away when correctly tensioned drive belts were loosened, we would replace the front main bearing shells with the next step smaller(uses select fit shells to "blueprint" the clearance). This only applied to a stock crank. There was a campaign(V06) on headgaskets for this engine. Sometimes the block would end up with excessive erosion around a certain water port in the deck in which case the block would be replaced. This would open up numerous possibilities regarding main and rod bearing clearances. It would help to know the complete history of the engine.

With the high miles some of these engines have now, we have started to see a few major engine failures. A while back I was able to check a rod bearing by simply picking it off the frame rail.......

BTW, valves are operated by shimmed buckets. No hydraulic lifters.

Man this place is cool

Thanks Oldsquirt, I guess I have some things to look into. $:-\$

The information is much appreciated...

GT

« **Reply #5 on:** October 10, 2010, 08:45:24 PM »

OK, so check this out.......

I took my mechanics stethoscope and found the noise to be coming from the drivers side head at about the middle in the valve cover...Took the valve cover off and started the engine. The knock is exactly camshaft speed (verified with a CSI 2130 vibration analyzer

) and seems to be the third lobe/valve back that is making all the racket....

What needs to be done?, I am thinking of simply pulling the front of the engine apart and removing the timing belt then camshaft and take a look see, there is literally no metal in the oil to speak of and it makes 35 pounds of oil pressure at idle (cold).

Does the head need to come off if the problem is in the cam follower? These heads look like they may have recently been rebuilt. The previous owner has very little information about it because she had only owned it for 18 months and spent over $2000 in repairs in the time she owned it and is very non mechanical.

Non of which were cylinder head related.

Ironically, it was leaking oil and it looks like it was the drivers side valve cover.

BTW 1993 Toyota 4 Runner 4X4 with V6 3.0L, auto, air, moonroof, cruise, tilt SR5 package and I picked it up for $1200....

The cheapest 4 cylinder I found was over $3k and it was pretty rough. $:-\$

Thanks again peeps, your awesome (I don't care what Brad says about you

)...

GT

« **Reply #6 on:** October 10, 2010, 09:19:01 PM »

Before tearing anything apart, you should at least check valve clearances(I .007-.011", E .009-.013" --Cold). Have seen a few cases where the lifter buckets have collapsed enough to be noisy. You do not have to pull the heads to service the buckets. Just pull the cam. NOTE!: There is a thrust flange on the cam that can break fairly easily. Remove cam caps evenly and make sure the cam comes straight up.

Spec for the bucket OD: 1.4930"-1.4934"
Spec for bore for bucket: 1.4945-1.4951"
Std oil clearance: .0011"-.0021"
max clearance: .0039"

« **Reply #7 on:** October 10, 2010, 11:07:19 PM »

Actually, you don't even need to pull the cam to change the shims. Spi and a few others make the tool....basically you pry the bucket down and then install a spacer that catches the edge of the bucket and holds it open. Give a little shot of compressed air at the cutout in the bucket and the shim will pop right out. Measure your clearance first, then measure your shim....determine what size shim you need to make it right. Those motors aren't bad. I probably did a few hundred of them during the VO6 campaign.

« **Reply #8 on:** October 10, 2010, 11:12:57 PM »

Quote from: Oldsquirt on October 10, 2010, 09:19:01 PM

Before tearing anything apart, you should at least check valve clearances(I .007-.011", E .009-.013" --Cold). Have seen a few cases where the lifter buckets have collapsed enough to be noisy. You do not have to pull the heads to service the buckets. Just pull the cam. NOTE!: There is a thrust flange on the cam that can break fairly easily. Remove cam caps evenly and make sure the cam comes straight up.

Spec for the bucket OD: 1.4930"-1.4934"
Spec for bore for bucket: 1.4945-1.4951"
Std oil clearance: .0011"-.0021"
max clearance: .0039"

Small update..I checked the cam to valve lash on the left head (the right looks like a three or four swear word job because of the intake plenum) and the measurements seemed reasonable. Right around .009" on the intakes and about .011" on the exhaust (+/- a tid bit)...

I did verify again where the knock was coming from, and it is at the third lobe...I'm thinking either a follower issue or a broken spring... $:-\$

I will keep you posted and get some pictures of my find....My daughter is stoked, she sat in it and made vroom vroom noises for 2 hours...(not literally LOL)...She really deserves this.

Well actually more, but this is what I can do for now.

BTW, this is a hard, loud knock that gets quiet for a few rhythms here and there at exactly half of engine RPM...

Thanks again!

GT

« **Reply #9 on:** October 10, 2010, 11:19:56 PM »

Quote from: lbhsbz on October 10, 2010, 11:07:19 PM

Actually, you don't even need to pull the cam to hang the shims. Spi and a few others make the tool....basically you pry the bucket down and then install a spacer that catches the edge of the bucket and holds it open. Give a little shot of compressed air at the cutout in the bucket and the shim will pop right out. Measure your clearance first, then measure your shim....determine what size shim you need to make it right. Those motors aren't bad. I probably did a few hundred of them during the vow campaign.

I am not convinced it is a lash issue, this sounds louder than a loose valve clearance to me, I can understand why they thought is was a rod, it was just too slow and inconsistent for me to believe it was in the bottom end...

If the follower was worn/broken around the skirt, could it be hitting the side of the bore causing this crazy noise? That is what I am starting to think.

GT

« **Reply #10 on:** October 11, 2010, 09:35:31 AM »

I've never seen the heads wear such that the lifters are flopping around and knocking.

I have seen a couple cases where a piece of debris got stuck between the shim and bucket causing the shim to rock on the bucket and wallow out the little recess that holds the shim firmly in the bucket.

Based on your measurements, the noise is not due to excessive clearance.

Rock the crank pulley back and forth and check for a broken cam maybe? Have you done a compression test yet? I've seen lots of burned valves on the center and rear cylinder on driver's side....some accompanied by strange noises.

« **Reply #11 on:** October 11, 2010, 01:14:15 PM »

After looking into the parts cost on a rebuild kit and speaking to my machinist, I have decided to tear the whole thing down to the bare block and build it. This thing has to get through 2 teen aged drivers and will need to be pretty reliable.

I think this way I can fix all the little oil leaks and have a nice fresh platform to work with...

My machinist says he can resurface the heads and the deck of the block where these tend to have issues with the head gaskets and seemed really familiar with the idiosyncrasies of these badboys..

Thank you guys very much for the help, your awesome.

GT

GT Jets

Toyota SOHC V6 3.0L question...

SuperJet

Re: Toyota SOHC V6 3.0L question...

GT Jets

Re: Toyota SOHC V6 3.0L question...

Oldsquirt

Re: Toyota SOHC V6 3.0L question...

GT Jets

Re: Toyota SOHC V6 3.0L question...

GT Jets

Re: Toyota SOHC V6 3.0L question...

Oldsquirt

Re: Toyota SOHC V6 3.0L question...

lbhsbz

Re: Toyota SOHC V6 3.0L question...

GT Jets

Re: Toyota SOHC V6 3.0L question...

GT Jets

Re: Toyota SOHC V6 3.0L question...

lbhsbz

Re: Toyota SOHC V6 3.0L question...

GT Jets

Re: Toyota SOHC V6 3.0L question...