MudHippy

Have a look for yourself.






So it happened like this.....a short time ago I returned from a trip with my rig running different than when I left. Wasn't quite sure what had happened, but she ran great 'til I got there and then on the ride home I(with my highly attuned ears)heard a distinctive change in the exhaust note. It frightened me quite a bit as it was very reminiscent of the sound it made when I blew the HG. Just not quite as loud. Anyway, it couldn't have been the HG again. It was installed, with utmost precision and care, by yours truly just 6000 miles ago. Next on my concern list(after *K.I.S.S. check)was the exhaust valve(s) I hadn't replaced at the same time as the HG. Despite their having 218k miles worth of wear, and on their "last legs" quite obviously. I didn't know for sure though. Something was DEFINETLY disturbing the idle (REALLY rough) and making a weird exhaust noise like a blown HG. Compression?

So...suspecting compression loss, of some sort, I check the compression. All good except #6. No improvement with added oil to cylinder. Hmmm....HG or valves then? NOPE! The valves and HG looked fine on all cylinders when I tore the heads off. But it had to be leaking from #6 cylinder somewhere right? Must be the rings then, though I wasn't quite seeing how(remember my compression test said rings O.K.). NOPE! Look what I find when I get to ol' #6 piston. That chunk came off with the lower compression ring which was pinched a little and sorta stuck when I tried to remove it. I forced it off and thought I'd carelessly done all the damage at that moment. Then I could see the carbon built up in the crack that was previously hidden behind the ring. I had just "finished the job" with the breaks at the ends(clean fractured metal visible). What isn't shown is the full path of the leakage(pic to be inserted soon). In the bottom ring groove (oil ring combo) there's an opening for oil flow through the piston skirt. The piece that broke off there was directly above it. Therefor a huge amount of blow-by was escaping down the crack and out through that hole essentially.

EDIT: Further inspection has revealed that the crack actually extends up and through to the bottom of the #1 compression ring groove. The cracked portion of which is now deformed(bent down slightly)and was pinching the #2 compression ring in it's groove.

Here's that other look.


Needless to say, I'm in the middle of a FULL rebuild.

Just wanted to share this much of it with y'all. I'd never seen or heard of a 3VZE cracking a piston. Had you?

*K.I.S.S.
Keep
It
Simple
Stupid!

Many problems are less complicated than they may appear! Always start with the stupid stuff! Give it a K.I.S.S. first!

snobdds

That sucks, but at least you have an optimistic attitude about it. It sounds like you could fix it and be back on the road in no time flat.

Good luck

thook

Mudhippy?! Haven't seen you around YT in a good while. Not that I've been around much myself for a little while, but I stop in here and there.

Anyway.........

Never seen that before, either. But, I do believe you push that motor rather hard sometimes, no? Any idea what your oil pressure or compression ratios were like before the failure?

Elton

ouch guess its time for a 3.4L

MudHippy

I've never owned an engine that I didn't eventually kill. This one is actually doing better than the rest.

All in good fun I always say!

I try to avoid this place. It ain't like it used to be....but I still find myself back for a look-around on occasion.

No way check the oil pressure, but the #6 had 110 psi and others right around 175 psi. Speeking of comp. ratios, I just ordered some NPR pistons w/9.3-1

I know your kidding...

Bumpin' Yota

Remind me to keep you away from my GTO and its LS1!! LOL! J/K!

NPR pistons with a higher CR?!? Please do tell - Im in the middle of a full rebuild as well, the 3vze is getting bored 30 over and it would be nice to put some better pistons in it...

Are they a custom build? If so can one specify a wee bit larger of a wrist pin hole? (To accept a 5vz-fe rod which is a beefier rod....)


ps - and if anythning was to get swapped into my yota, it would be a LQ9 forged 6.0 with L93 heads a turbo setup with a 4L65e. I would then break parts at will south of the tranny!

MudHippy

Well, I haven't any real way to confirm they are truly 9.3-1 pistons. I bought a them as a cheapo piston set(w/rings & pins incl.) off ebay. Don't have them yet, but I have paid for a few cheapo parts off ebay that weren't as they should be(more on that in a sec). So "Buyer Beware" on these, but here's where I found them.

http://cgi.ebay.com/ebaymotors/88-95...QQcmdZViewItem


And next up...

Have you ever seen upside down 3VZE head gaskets?

Check these out.



I plan on dedicating a new thread to those babies. What a JOKE!!!! I should have seen it coming though, the pics on the site I got those from had me fooled. All the way 'till I went to put one on then.......uhhhhh wait a minute....somethings not right here......


Ya live ya learn!

WARNING!
DO NOT BUY THESE GASKET SETS CONTAINING FAKE HEAD GASKETS!

http://cgi.ebay.com/ebaymotors/88-95...item2c58e9a5ad

http://cgi.ebay.com/ebaymotors/88-95...item20b545f9b2

http://cgi.ebay.com/ebaymotors/88-95...item1c1731e9a6

For those not "in the know", the white silicone/graphite side of the gasket should face the block with the coated steel side facing the head surface. Impossible with the gaskets shown above.

Go to partsdinosaur.com and get the gaskets he sells. I've bought 2 sets of "real" HG's from there. He's also got great deals on everything you need, parts wise at least, to rebuild almost any Toyota engine.

Oh, and about engines, I had always planned on "blowin' up" this V6(had 206k when I bought the truck) and throwin' in a 4.3L Vortec(3.4L?! PUHLLEEEEZZZZ AS IF!!!!). But I've grown rather found of her over the years, AND she ain't going down without a strong fight it appears.

thook

This is before the indicent?

I didn't necessarily mean anything imperical on the oil press. Just in case you happened to notice the pressure guage beforehand.

thook

Anytime is a good time for a 3.4....

MudHippy

I did mean at the time of the incident, actually. I forgot to mention that I don't have a gauge in my dash, just a light. I've got an oil pressure sensor(light comes on when pressure sensed hits min.) and not an oil pressure sender(sends pressure readings to a gauge). The light didn't happen to come on, so it wasn't too low(supposedly). Sorry for the initial lack of specifics there.

I do have an after-market dash mountable oil pressure gauge a buddy gave me....somewhere. I just haven't got around to finding a spot for it in my cab and plumbing it in yet.

yoterr

ouch that sucks, at least you gots the time to do it!, and yeah the ebay thing has burned me a couple times....but you get what you pay for i guess, lets see...i bought a front end kit from egay (tie rods pitman and idler) and the friggin inner tie rods are longer....wtf but ooooowell have fun!

MudHippy

Here's that kit I bought.


The pistons look a little different than stock. They sure aren't NPR pistons(as advertised)either, ITM I guess?


I'll check my compression #'s when the rings get broke-in.

We'll see if they differ greatly from the stock(9.0-1)#'s I had previously. I should mention I had my heads resurfaced prior to the first measurements. So I don't know exactly what my compression ratio was at that time or exactly what it will be when I'm done for that matter. I do know the amount material removed from the heads was very minimal and is probably not raising the compression ratio too much.