FZJ80 Head Question (1 Viewer)

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

Joined
Jan 16, 2003
Threads
24
Messages
65
Website
www.virginiacoachworks.com
Hey guys, just bought a FZJ80 for a hell of a deal, knowing that it had head problems. I could use some advice on two fronts: Diagnosing the cause and Determining the Cost to Fix

The problem I see is when driving it, the engine shutters, real quick vibrations that feels like hesitation. This is most prevelant at a range of 2.2k to 3.5k, but probably is just not noticeable below. It's bad enough that the vehicle vibrates. The engine seems to cool fine, but the exhaust is fire hot and gives a slightly sulfer smell. Also, the check engine light has come one. The previous owner, says it has a burnt valve and the vibration is backpressure. Someone else told me that it's a blown headgasket. I'm interested in your alls opinions on it though.

As far as price, heres the poop. I've acquired an extremely low mileage head that I can swap out, but the mechanic I talked to told me $1200 in labor just to bolt on the new head or swap the gasket if that's all it needed. Beyond that, it's 250 for gasket set and 250 for head bolts, which I'm told cannot be reused, they are "stretch bolts"

I'm pretty new to all of these new fangled engines. I was ready to jerk the head off, replace the gaskets and put the new one on, torque it down and drive. But I'm afraid I'd miss something.

Here's your license, call BS on me and tell me what you think

Thanks
Todd
 
I could be wrong, but in all the cases of any car/truck I've evern had or known that had a bad head gasket, there was some sort of leakage--either coolant with oil, coolant into the cylinders, oil into cylinders, exhaust spitting out the side...you name it. If you're not getting some/all of those, I'd be curious to know what's up with the gasket. I'd be surprised if that's all it was.

The $1200 for the mech to replace the gasket doesn't sound too far off, having just gone thru this. They've gotta pull a lot of stuff out/off of the engine to do the replacement. I'm not sure about the stretch-bolt thing...when they replaced my head gasket, I don't remember seeing anything like that on the invoice. Maybe they're included in the gasket kit if it's a required replacement--CDan will know.

Hot exhaust with sulphur smell sounds plausible, but I'm not an expert. Wouldn't a bad valve give you problems at all speeds? Could be a fuel problem too?
 
I'd do a compression check first to see if that helps shed so light on your probelm. Also get the code pulled. On earlier models that can be done with a paper clip. Didn't see your year so without that we're going to be limited to what help we can offer.
 
Todd,

It is true that the head bolts are what is refered to as "plastic region bolts". They are not an automatic replacement. The diameter at a specific point is measured. If it is below minimum diameter the bolt needs to be replaced.

The sulpher odor is due to the chemical makeup of the gasoline.

I wonder if you have a fuel delivery problem?
 
Todd,
Before just sticking in a new head gasket I would get the head checked for flat. If the other head you got is used the same thing would apply. If the engine was overheated the head could be warped.
Scamper - I had a head gasket one one of my backhoes blow between cylinders. It resulted in running rough and would overheat only if run hard; otherwise ran fine. Eventually it cracked the block. The compression check that Rick recommended would find this.
As far as the exhaust goes some thoughts are clogged cats - say from leaded gas being used at some time. Also a crimped or smashed exhaust. Getting the code may help point you in the right direction. Hope this helps.
Bill
 
I would check the catalytic convertor(s) before diving into the motor. Sulfur and high back pressure may indicate clogged/failing cat.

It's a lot of labor to get the head off, unfortunately.
 
Thanks guys, that's all good information. Some answers to your questions/mentions

It's a 95 model

Has brand new cats - which makes me think there was a problem before

Shuttering only appears to be bad at certain rev rates mentioned before, and they did lessen the longer I drove it

The prices I've gotten so far, just from describing the problems over the phone and knowing that they could change (not likely lower) are $3000 from Toy, $2000 from a private shop and $1000 from a friend's friend who is a master mechanic.

My struggle is probably pretty common, I think I could figure this all out on my own and would cost about $400 in parts, but like somone said here, it's a ton of work to take everything off and reassemble correctly. I'm grousing out loud, but in the end I guess I should have someone experienced do this.

Here's the other thing (warning, rambling ahead), I've taken plenty of heads off and reassembled, but a friend of mine told me that there is a lot of timing involved with degreeing the cams on these engines. That I would need SST to do this and hell of a manual? So I thought, if I could mark the head as it is, pull it, and ascertain the problem, then I could either just replace the gasket, or the head and gasket and then put the cams back to the marks or use these marks to set the new head. Does this sound insane?

Again, thanks for your comments.

Todd
 
Bill--you're right. I hadn't thought about the between-cylinder breach (have never seen it myself either, but it makes sense).??? Might that might also explain the hot exhaust, due to unburned fuel from the "adjacent" cylinder being pushed out without burning during the compression stroke? Might also have fried the valves in question?

Tom
 
A between cylinder breech would, I think, show low adjacent cylinders. That could also be bad valves in adjacent cylinders. A bore scope would be handy in that case to get a look-see. Also, a cylinder leak-down test would probably give an idea about where it's going.
 
Doesn't 95s fall into the paperclip read out of the codes! I have a 96 which I thought was the first year for OBDII. If I'm right do that read out first and post the error code(s). How many miles on the rig? I've seen bad or worn ignition systems do this as well. What wires, plugs cap are on the truck? All aftermarket or near needing a change anyway! Again do the compression check, cheap tool and easy to do!

Don't over think this! Odds are that it is not a big problem and doing some simple easy checks first might save you some cash.
 
I'm not familiar with the paperclip test you're referring to, although I imagine it has something to do with jimmy'ing a diagnosis code from the computer?

If someone can tell me how to do it I'll try it tonight. The truck has 190k on it and it is as tight as new, as far as the diffs and tranny. I had a 91 with half the miles that was really sloppy, thunking everytime I accelerated. This one is as solid as the 96 I bought new, back in the day (single and stupid enough to spend $50k on a car)

Thanks
Todd
 
Hey no insult meant to anyone who has spent $50k on their car, I just meant that I no longer control my cajunas, and my wife would cut them off if I spent that much now.

:D Todd
 
Coachconverter,
All the responses you have gotten are good. I know from a recent (non-LC) problem I worked on relating to the valves this, if it was an intake valve not working correctly you would experience back firing through the intake, the exhaust valve if burnt or cracked would exihbit terrible idle and cause your exhaust to over heat do to unburnt fuel entering the exhaust.
A valve problem (from my experience) would NOT be limited to a rpm range and would be constant, UNLESS it is a sticky valve, even so I don't believe it would be in a limited rpm range.
First thing is to check the code. That may help allot.
It could also be as simple as a fuel filter, lack of correct fuel pressure would cause both poor performance (vibration from misfiring) and also could over heat the exhaust due to a lean fuel condition. So do more checking before you start yanking the head and paying big bucks. Check the code. Heck it could even be one plug not firing.

Yomama
 
95's are OBDII.


True 95's that is. Jan 95 up. These also have airbags. Sometimes late 94's (8/94-12/94) are accused of being 95's because usually Toyota's model years change in August or September, but not always.


Yet another worthless bit of triva for y'all....... ;)
 
[quote author=coachconverter link=board=2;threadid=4533;start=msg34074#msg34074 date=1061571525]


My struggle is probably pretty common, I think I could figure this all out on my own and would cost about $400 in parts, but like somone said here, it's a ton of work to take everything off and reassemble correctly. I'm grousing out loud, but in the end I guess I should have someone experienced do this.

Here's the other thing (warning, rambling ahead), I've taken plenty of heads off and reassembled, but a friend of mine told me that there is a lot of timing involved with degreeing the cams on these engines. That I would need SST to do this and hell of a manual[/quote]

If you've got some tools, it's not a big deal to pull the head. All it takes is some time & garage space, and I would get a factory manual to help you along. Having a hoist to lift the head off would be helpful as it's awkward to lean in there to lift it out.

It also provides you a good opportunity to pull the injectors for cleaning as well as replace all the cooling/heating system hoses. IMO if you have the time, it's worth doing yourself.

I did not use any SSTs to pull the head.

I concur on the leakdown test.
 
[quote author=cruiserdan link=board=2;threadid=4533;start=msg34123#msg34123 date=1061577218]
True 95's that is. Jan 95 up. These also have airbags. Sometimes late 94's (8/94-12/94) are accused of being 95's because usually Toyota's model years change in August or September, but not always.
[/quote]

So my 12/94 truck could have been sold as a 95?

A 95 w/ an A442F and no lame airbags? :D
 
[quote author=Rogue link=board=2;threadid=4533;start=msg34260#msg34260 date=1061602329]
So my 12/94 truck could have been sold as a 95?

A 95 w/ an A442F and no lame airbags? :D
[/quote]
Don't worry Rogue - YOU are lame so that makes up for it. :flipoff2: Yes, the 12/94 would have definitely been a 95 no? Wasn't 95 also the bastardized year? Half OBDII but not true?
 
[quote author=Junk link=board=2;threadid=4533;start=msg34264#msg34264 date=1061602618]
Don't worry Rogue - YOU are lame so that makes up for it. :flipoff2: Yes, the 12/94 would have definitely been a 95 no? Wasn't 95 also the bastardized year? Half OBDII but not true?
[/quote]

As long as I have my trusty paperclip on board I never worry about the OBDII garbage. :flipoff2: Shhh... Don't tell anybody here at BYU that I used that smiley. :D
 

Users who are viewing this thread

Back
Top Bottom