(Excuse the crosspost, need to figure out what I'm going to do today before I go back to the shop tomorrow AM)
In the process of swapping a 3.4 into my '90. Did compression test before pulling the engine and leak down test after, and 5 cylinders held between 78%-92% pressure. Cylinder #3 had lower compression and only held 64%. mostly leaking from exhaust valves, so I decided to pull the heads while the engine was out on the stand, and get them resurfaced. Cheaped out and went to a new machine shop to save $50 and 15 mins driving, thinking it should be a run-of-the-mill job that anyone could handle. Got them back Friday PM, put RH head on its side and naptha over the exhaust valves - they were still leaking, although it seemed a little slower the same test before rebuild. Set heads on the block and checked valve lash, 6 of 24 clearances out of spec, so had to deal with that too.
Finally got them bolted on late yesterday and did another leakdown test. Cylinder #1 held 86% pressure before valve job, it now holds 52% (mostly leaking from intake valves). Cyl #2 used to hold 83%, now holds 50% (leaking more from exhaust valves it seems). Cyl #3 did go up, from 64% to 70%. I stopped there because one intake valve on #4 has zero clearance from swapping shims to fix their lash FU, and because I'd seen enough. So after banging my head on the wall for a few hours I went to bed, confirmed the numbers again this AM, and now I'm here. Will pull the cams and check the rest of the cylinders later.
Has anyone seen this before? Without removing valves to measure yet, is it possible they cut the angles wrong and the valves can be saved by a competent shop, or more likely that they removed too much material and I have to buy all new valves? I see in the FSM they spec a minimum valves length, which would imply that there's also a maximum allowable amount of material that can be removed from the seats, yes? What would you do? I'm torn between trying another shop or starting fresh with reman heads from Ebay, especially if I have to buy all new valves. Looks like I'm out the $100 for another set of head gaskets either way, say nothing of hours and hours more labor.
That's a real bummer. You can't really do two valve jobs on the same valves, best to replace. I'd let the shop know of the issues and ask for a refund (don't let them do it again).
That's a real bummer. You can't really do two valve jobs on the same valves, best to replace. I'd let the shop know of the issues and ask for a refund (don't let them do it again).
Thanks for the reply. Was afraid of that, looks like I can get DNJ valves from Yotashop for $7 and $9 or OEM for $11 and $15. Or some prebuilt Ebay heads of unknown provenance, That were at least pressure tested for $780 Ugh
I wrote them a check at around 5PM Fri, was planning to issue a stop payment as soon as my bank open Monday AM and take the refund issue out of their hands entirely. They're going to cost me hundreds here, no way they should get paid $520 for doing much worse than nothing.
If you're in NH take them to KJE Automotive Machine in Rochester. They'll make them beautiful for about $550.
I'm a ways from Rochester but I'll keep them in mind. Do they have a pressure/vacuum tester? Really all depends on what the valves look like. If they can't be resurfaced again and still have enough material left to transfer heat efficiently I'm leaning towards shelling out for some tested Ebay heads rather than spending $300 on valves and another $500 on machine work.
Anyone else dealt with some bad machine work please chime in, I'm headed down to tear the heads apart, again, now and bringing them back tomorrow AM.
Anyone else dealt with some bad machine work please chime in, I'm headed down to tear the heads apart, again, now and bringing them back tomorrow AM.
I've been doing this a while so the short answer is yes, I have seen blocks over bored, valves ground wrong, parts lost, heads ground crooked, etc. I have two machine shops I deal with, one will press bearings, grind flywheels on the spot for me and is cheaper on rebuilding heads but has a long turn around time and will lose any hardware that I forget to remove from the head, but does a good job. The other, KJE, is a little more money, but one day turn around and the head is like new with a mirror finish.
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98 SR5 4X4 5spd, desert dune metallic, Toytech Eibach 3" lift, 1" body lift, RAD Rubber Designs splash guards, 4XInnovations bumpers, Doug Thorely Headers, Magna-flow converter, JBA muffler & tail pipe, RCI skid plate, SPC UCA's & rear LCA's, front sway bar links on rear, gen II rear links on front, Tundra brakes, '02 headlights, tail lights & sidemarkers, BFG 255/85R16 Mud Terrain T/A's 241,000 miles.
Against my better judgement I am letting the shop take another look at them, if only to see how bad his guy messed them up. He says he'll buy new OEM gaskets and OEM stretch bolts, which would ease the financial pain on my end, and make it worthwhile vs finding a different shop and starting from scratch at this point. Not leaving the shop until I pressure test every cylinder and valve clearance, and check a few valves to make sure they're still within all specs after all this tool work.
I've dealt with some real winners when it comes to machine work... I restore muscle cars mostly so... having had a resto shop for years... i've seen it all.
I had an engine come into the shop and ran poorly - vac leaks everywhere... couldnt make it happy. Owner gave me permission for a tear-down and I caught it when the block was bare... deck height on one side was higher than the other... dumbasses had only decked one head surface.
I've seen heads screwed up every which way you can imagine (and some you cant)
^Geesh. Knowing what I know now, I'll never bolt a head on without pressure testing it first again. Just wish I knew before - or didn't have cause to know at all.
Just back from the machine shop dropping off the other head. Owner said they called the seat grinder manufacturer and he told them to measure some things and they found some things out of spec. Not sure I entirely buy that as the sole cause since in the vid above one valve looks to hold pressure and the other bubbles like mad and is probably losing the bulk of that 50% leakage, but...as long as they come back good this time, I guess. He said valves don't need any more work so I shouldn't have to buy any of them at least.
Even if the machine's alignment were the sole cause I wonder how many heads they've recently sent out the door with worse compression than when they came in, that people have bolted on a driven without checking, like I almost did.
It's a P.I.T.A. but it may be worthwhile to assemble cams and adjust lash on the bench just to be sure.
I will probably make sure I can get .001 under cams at the timing marks this time around in case there are any clearance issues which can't be solved with shims, rather than take for granted that things were done correctly. Need to fab a custom exhaust crossover for this engine swap before I drop it in the truck, so need the manifolds on to weld that up, which is why I'm in a yank to get the heads on. Then more custom exhaust work to do after the engine is in, which I can at least start while I wait for shims to come in, if I have to buy any.
Heads came back today, all cylinders holding between 87-96% now. With 180k on the untouched block I'm happy with those numbers. Shop bought me new Toyota gaskets and head bolts as well.
Ugh
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