FZJ80 Rough Idle / Misfire P0300, P0303 & P0304 (1 Viewer)

[landtank]

With those compression numbers even if off half as much and it was my engine, I'd pull the cams and do a 3 pass re-torque to 85 ft-lb and see what happens.

The proper torquing of a HG is to torque the head to 29 ft-lb and then do 2 90* turns on the bolts. I've seen one where they only torqued to 29 ft-lb and skipped that second step.

 

[dieseldog]

A shop doing a compression test and stated "149 psi but didn't hold for long"?

If that was their exact statement, then find a different shop. Seriously.

A proper compression test is done with the engine rotating, the throttle held open, ignition unplugged, spark plug removed with a gauge fitted into the cylinder and the engine at operating temp. It is a "maximum" reading over three compression cycles.

After it's done "dry" then a "wet" test should be done immediately following.

Otherwise, they would be doing a leakdown test, and that determines whether the valves are leaking or the rings are leaking.

@dieseldog what's the name of the shop you recommend in H?

That would be Javier's Autos Unlimited, 9443 Clay Rd., Houston, TX 77080. 713-461-5595. Talk to Stewart about scheduling.

 

[txoil]

That would be Javier's Autos Unlimited, 9443 Clay Rd., Houston, TX 77080. 713-461-5595. Talk to Stewart about scheduling.

Thanks Bilt4me, landtank and dieseldogs. This is all new territory for me so all these ideas are helpful. I tracked down Javier’s and Duggys. Duggys can get me in earlier, on Tue. Should I wait for Javier’s? Anyone have a view on Duggys? PM me if you think more appropriate. Thanks!

 

[txoil]

Thanks Bilt4me, landtank and dieseldogs. This is all new territory for me so all these ideas are helpful. I tracked down Javier’s and Duggys. Duggys can get me in earlier, on Tue. Should I wait for Javier’s? Anyone have a view on Duggys? PM me if you think more appropriate. Thanks!

Did more research. Calling Stewart again on Mon. Thanks much!

 

[txoil]

I'm still thinking about this one but it's hard to believe the engine would even run with only 30psi on half of the cylinders.

Are there any other symptoms? Oil in coolant or coolant in oil? Excessive smoke? A flashing cel isn't a good sign unless it's in test mode.

When I read the shop said the injectors "appear" to be seated does that mean they pulled everything apart to look? Not trying to bash on the shop but that's a decent amount of work for a random check. Does the shop have access to the factory service manual?

Keep a lookout for a known good used engine. Any kind of swap will likely cost more than you want to pay. Nothing about a swap is drop in on these.

No oil in coolant that I can see (coolant reservoir is new and level is still at Full and bright red). No white smoke or smoke at all from tailpipe on startup.

The rough idle is only at low speeds and even more pronounced when the brake peddle is on. Engine smooth though noticeably underpowered at mid to high speeds.

 

[txoil]

Stewart at Javier's took a look. Blown HG between cyls 3 and 4. Said it didn't even take 5 mins or a pressure test to diagnose. $5k fix. He and Javier gave me a lot of comfort on their level of knowledge and experience.

 

[txoil]

update: due to timing issues ended up having to take it to an engine specialist downtown, with Stewart’s blessing. This new shop diagnosed a blown Hg between 3 and 4 after opening it up. Will post photos. Then they said the head has also been shaved by 25 mils, which puts it out of spec to be reused or Re installed. Then said there were ridges in the cylinder which required machining out and decking the short block. Effectively a full engine rebuild for $14k total. Does this sound right? HG replacement now a full blown rebuild?

Thoughts much appreciated, thank you in advance.

 

[Malleus]

First things first: I assume by mils they mean thousandths of an inch (pet peeve; no machinist measures in mils). So exactly how do they know how much was taken off? There is no machined reference flat on the top of the head to use to identify the original thickness.

Second: how far out of flat is the head? If it's not warped out of spec, why cut it?

FWIW, I've had a machinist I trust tell me that the 1FZ-FE heads were listed at a maximum material removal so that Toyota wouldn't be responsible for undermining the EPA restrictions on exhaust gas volume per cycle. This necessarily happens when you remove material form the underside of the head, because the valve openings are conical and not cylindrical. All that's required is to move the valve up, or cut the top off, whichever is appropriate for the amount of material removed, and to match the cams.

If you have ring ridges that can't be polished out, yes you're in for a complete lower end machining, and at that point you need to replace all the wear items. It's pretty much been determined that, as of now, a new short block is cheaper than a rebuild, by far.

It doesn't sound like you have to toss the head though. I'd get a second opinion on the condition before I threw it away.

 

[BILT4ME]

update: due to timing issues ended up having to take it to an engine specialist downtown, with Stewart’s blessing. This new shop diagnosed a blown Hg between 3 and 4 after opening it up. Will post photos. Then they said the head has also been shaved by 25 mils, which puts it out of spec to be reused or Re installed. Then said there were ridges in the cylinder which required machining out and decking the short block. Effectively a full engine rebuild for $14k total. Does this sound right? HG replacement now a full blown rebuild?

Thoughts much appreciated, thank you in advance.

I highly doubt that there are ring ridges on this block at 222K based on the number of engines opened up and pics shown on this forum, then put back together witout even a re-hone. They still have the original cross-hatching on the cylinder walls.

Unless this was run HARD and they didn't change the oil, that would be unusual. Not to say it isn't, but i think you need a face to face on that block and see it for yourself. if you can catch a fingernail on the ring ridge, then yes.

 

[landtank]

If the head indeed was cut that much why not order a custom thickness MLS gasket to compensate for the lost height,

In my opinion there is a big gap between acceptable and perfection and most insist that perfection is the only acceptable outcome.

If the head is truly gone and the block is trashed look into a new short block to start with. That might be cheaper than what they will charge to rework the one you have.

 

[Malleus]

Again, I'd be interested in knowing how a shop which did not cut a head, knew how much another shop did.

 

[txoil]

update: due to timing issues ended up having to take it to an engine specialist downtown, with Stewart’s blessing. This new shop diagnosed a blown Hg between 3 and 4 after opening it up. Will post photos. Then they said the head has also been shaved by 25 mils, which puts it out of spec to be reused or Re installed. Then said there were ridges in the cylinder which required machining out and decking the short block. Effectively a full engine rebuild for $14k total. Does this sound right? HG replacement now a full blown rebuild?

Thoughts much appreciated, thank you in advance.

First things first: I assume by mils they mean thousandths of an inch (pet peeve; no machinist measures in mils). So exactly how do they know how much was taken off? There is no machined reference flat on the top of the head to use to identify the original thickness.

Second: how far out of flat is the head? If it's not warped out of spec, why cut it?

FWIW, I've had a machinist I trust tell me that the 1FZ-FE heads were listed at a maximum material removal so that Toyota wouldn't be responsible for undermining the EPA restrictions on exhaust gas volume per cycle. This necessarily happens when you remove material form the underside of the head, because the valve openings are conical and not cylindrical. All that's required is to move the valve up, or cut the top off, whichever is appropriate for the amount of material removed, and to match the cams.

If you have ring ridges that can't be polished out, yes you're in for a complete lower end machining, and at that point you need to replace all the wear items. It's pretty much been determined that, as of now, a new short block is cheaper than a rebuild, by far.

It doesn't sound like you have to toss the head though. I'd get a second opinion on the condition before I threw it away.

Thanks. Yes 0.025 inches is what they told me. I don’t know how out of shape the head is and how they measured it. Will ask them. I understand from Stewart ridges do occur normally in these engines but I don’t have any benchmark as to how much is too much. I’m trying to post a video in which the shop explained to me what they found.

 

[txoil]

If the head indeed was cut that much why not order a custom thickness MLS gasket to compensate for the lost height,

In my opinion there is a big gap between acceptable and perfection and most insist that perfection is the only acceptable outcome.

If the head is truly gone and the block is trashed look into a new short block to start with. That might be cheaper than what they will charge to rework the one you have.

Makes sense to me. Thanks.

 

[txoil]

Video of blown HG and ridges in short block.

 

[Malleus]

Those "ridges" are at the top of the piston stroke. The piston rings don't get up that far. Those bores will polish out with a ball hone.

His point about the head gasket pieces getting into the engine would be valid if there was evidence of that in the bores. I don't see any; but I'm not there and the video doesn't show the entire bore surfaces.

Has this shop ever built a 1FZ-FE before?

Unless you're sitting on a great deal of cash you need to spend, I'd say you're looking at a head refresh (flatten lower surface as needed, replace valve seals, grind valves) and put it back on the block. I'd run that engine, if there was nothing in the oil.

Maybe it's time to get a second opinion from someone local.

 

[Malleus]

Just so you know for sure what is and isn't acceptable, these are the limits for flatness for head and block:

These aren't my opinions; they're the published data from Toyota in their factory service manual, for the 1995 year model (applies to all 1FZZ-FE engines). Nowhere in here does is specify that "25 mils" (which, again, I'm interpreting to mean 0.025-inch) is an acceptable material removal. So I still have no idea how someone came up with that number.

Further, he doesn't show it in the video you posted, but if he didn't scrape the old headgasket off the block (and I don't know of any shop that would, before they were given the job), he can't possibly know the block needs to be cut. FWIW, the cast iron blocks used in these engines rarely require machining due to a blown headgasket. I recently replaced a blown headgasket on one of mine with over 300k miles on it and the block was dead flat.

If this shop is advising you what they would do in most cases for an engine with a blown headgasket, you are talking to the wrong people. They aren't spending their money, they're spending yours. You need a shop that will assess your problem and tell you what you need to do, at a minimum, for that engine, not what they would do if they had an unlimited budget.

I'd hate to see you get talked into spending more on this repair than your truck is worth.

 

[landtank]

Again, I'd be interested in knowing how a shop which did not cut a head, knew how much another shop did.

I suppose one method would be to mesure the cc volume of the chamber.

 

[Malleus]

I suppose one method would be to mesure the cc volume of the chamber.

Yeah, but I'd bet real money that didn't happen here.

 

[landtank]

Yeah, but I'd bet real money that didn't happen here.

well, when you look at a carbon ridge and state it's one of the reasons for a 14,000.00 rebuild, you might be looking for a payday.

 

[Malleus]

well, when you look at a carbon ridge and state it's one of the reasons for a 14,000.00 rebuild, you might be looking for a payday.

no doubt; hence my rant