Cracked head :(

[amalik]

^^^ this is why I'm teaching myself to wrench my own junk. Finding the right guy to do your work for you is hard when you don't know what you're looking for, and the thought of dropping hard earned cash on the wrong guy is scary.

I like this post... except that doing something wrong in an *engine rebuild* process is not forgiving. Especially when you get everything back together, and THEN discover you did something wrong.

Now if it's a spare rig and not a DD, then fine... Maybe you can afford another 12 hours+ taking the engine apart again.

 

[Scramble]

Yeah, they'll have an OEM Toyota built engine alright. That's what they are looking to replace. An OEM Toyota built engine that was neglected, and now needs work or replacement.

I for the life of me will never understand why swapping in a mystery engine with 100k+ miles, is considered a great idea, but a properly rebuilt engine is frowned upon.

It's true there are apparently a lot of hacks out there claiming to be Mechanics, that aren't qualified to rebuild a LEGO® car, let alone a real car. But there are also qualified Mechanics out there that can build an engine to better than OEM specification.

If the block and rotating assembly are in good condition, I wouldn't hesitate to replace the head(s) properly, and drive on with confidence. Instead of installing a used engine, which could be on it's last legs as well.

That's why I had my heads rebuilt. I'm the original owner & took care of the motor.

 

[Scramble]

Jay,

Getting heads re-machined though should not cost that much, relatively. Right?

If they're cracked you need new or refurbished one's.

 

[amalik]

If they're cracked you need new or refurbished one's.

Then what do people mean when they say getting heads machined? Just cleaned, polished?

 

[kball]

It has high mileage, 222k, but runs and drives nicely.

All this talk of heads and rebuilds... I don't see the problem. Add some coolant as necessary and drive on until it doesn't drive nicely.

Oh and how does your mechanic know it has cracked heads and not just head gasket issues?

 

[Scramble]

Then what do people mean when they say getting heads machined? Just cleaned, polished?

They're refinishing or machining the area that meets the head gasket.
I sent mine out to get machined & it had a crack so I was out a couple of hundred & still had to buy a new one. It's aluminum, I gambled & lost.

 

[kball]

Then what do people mean when they say getting heads machined? Just cleaned, polished?

Yes, they check for cracks and if there isn't any they machine them to make the surface pristine for the new gasket. Once cracked it's whacked.

 

[02SE]

Then what do people mean when they say getting heads machined? Just cleaned, polished?

Machined could mean surfacing the head so it is flat within specified tolerance and has the correct RA for the type of headgasket being used, cutting new valve seats, machining new valve guides, welding up and machining damage to the combustion chamber, etc.

 

[ASUMTNEER]

All this talk of heads and rebuilds... I don't see the problem. Add some coolant as necessary and drive on until it doesn't drive nicely.

Oh and how does your mechanic know it has cracked heads and not just head gasket issues?

I'm picking it up today and am going to run it like this until I make a decision on what I want to do. It still runs fine, so I'll just feed it coolant and drive on. Not sure how he determined the crack, but I trust he wouldn't rip me off as he is a family friend. He actually suggested me putting in a used engine with lower mileage.

 

[Appntr]

I'm picking it up today and am going to run it like this until I make a decision on what I want to do. It still runs fine, so I'll just feed it coolant and drive on. Not sure how he determined the crack, but I trust he wouldn't rip me off as he is a family friend. He actually suggested me putting in a used engine with lower mileage.

Who in Boone did the diagnosis? If it was done in Boone. I lived there for 9 years and know the majority of the good tech's in town and still see them on a regular basis when I come up for football games and other alum shenanigans. Drank a lot of beer in the back of some of the shops up there over the years haha. I'd put the money into fixing the 4runner if it was me. Youll still be way under the value of that vehicle and know its good to go for a while.

If it is in fact cracked heads, and you are sure of that, I can get you a set of heads from a 3.4 Tacoma with around 100k on them when the engine was pulled for some issues with the rings. The engine is down here in Durham, but I am sure I could get the heads up to you in Boone.

 

[kball]

That's my point, if the head is cracked it can't run fine, not all the time anyway. Usually it will run rough in the morning until it warms up and the crack closes up due to metal expansion. If you aren't getting any white smoke or rough running when you first start it cold I doubt seriously you have a cracked head or gasket issue.

Is there much rust on the underside of the truck?

 

[ASUMTNEER]

Who in Boone did the diagnosis? If it was done in Boone. I lived there for 9 years and know the majority of the good tech's in town and still see them on a regular basis when I come up for football games and other alum shenanigans. Drank a lot of beer in the back of some of the shops up there over the years haha. I'd put the money into fixing the 4runner if it was me. Youll still be way under the value of that vehicle and know its good to go for a while.

If it is in fact cracked heads, and you are sure of that, I can get you a set of heads from a 3.4 Tacoma with around 100k on them when the engine was pulled for some issues with the rings. The engine is down here in Durham, but I am sure I could get the heads up to you in Boone.

It was one of the techs at the Toyota dealership here. He is a good family friend and knows his Toyota's very well. How much for the heads?

 

[ASUMTNEER]

That's my point, if the head is cracked it can't run fine, not all the time anyway. Usually it will run rough in the morning until it warms up and the crack closes up due to metal expansion. If you aren't getting any white smoke or rough running when you first start it cold I doubt seriously you have a cracked head or gasket issue.

Is there much rust on the underside of the truck?

Almost no rust underneath, just the superficial surface rust at welds. The frame is solid. It runs rough in the mornings, but just for roughly 30 seconds. I haven't noticed any white smoke though.

 

[kball]

Almost no rust underneath, just the superficial surface rust at welds. The frame is solid. It runs rough in the mornings, but just for roughly 30 seconds. I haven't noticed any white smoke though.

That's the first thing you've said that actually points to coolant possibly leaking into a cylinder. With no white smoke it's still a little iffy. There's no way for the mechanic to tell if the heads cracked until they pull the head so I still don't get that diagnosis.

 

[ASUMTNEER]

That's the first thing you've said that actually points to coolant possibly leaking into a cylinder. With no white smoke it's still a little iffy. There's no way for the mechanic to tell if the heads cracked until they pull the head so I still don't get that diagnosis.

Probably should've mentioned that before, my bad. Coolant will disappear from the overflow as the car sits in the driveway. No visible signs of leaks. If the car sits just overnight, the cold start up is pretty normal and smooth. If the car sits over a couple of days, the cold start up is pretty rough. There may be minimal white smoke, but definitely not anything highly noticeable. When I purchased the car the CEL was on for what the PO told me was an evap code (he said bad gas cap). I got it for $2k, so I just took his word for it. I checked the code later and it was P0303, misfire on cylinder #3, cleared the code and it never returned (over 300 miles of driving). In retrospect, I should've led with this information.

 

[Appntr]

Probably should've mentioned that before, my bad. Coolant will disappear from the overflow as the car sits in the driveway. No visible signs of leaks. If the car sits just overnight, the cold start up is pretty normal and smooth. If the car sits over a couple of days, the cold start up is pretty rough. There may be minimal white smoke, but definitely not anything highly noticeable. When I purchased the car the CEL was on for what the PO told me was an evap code (he said bad gas cap). I got it for $2k, so I just took his word for it. I checked the code later and it was P0303, misfire on cylinder #3, cleared the code and it never returned (over 300 miles of driving). In retrospect, I should've led with this information.

The coolant disappearing from the overflow kind of needs to be taken with a grain of salt. There is less pressure built up in the system so the volume of the coolant can decrease therefore it wont overflow into the reservoir. Thats why there is a "Hot" and a "cold" line on almost every overflow reservoir. Its just not an accurate way to diagnose anything unfortunately. If you were burning coolant or had a head gasket leaking, I would expect to see some variation in the color of the oil as well. I just don't get how it was diagnosed as a crack in the head without exhausting all other options and pulling the heads to have them magnafluxed.

What constitutes the startup after a couple of days of sitting as "rough". Surging idle, drivetrain shaking more than normal vibrations?

A rough start up could be something as simple as a dirty fuel filter or some restriction in the fuel system causing the truck to starve for fuel til fuel pressure is built up completely in the entire system.

 

[ASUMTNEER]

What constitutes the startup after a couple of days of sitting as "rough". Surging idle, drivetrain shaking more than normal vibrations?

A rough start up could be something as simple as a dirty fuel filter or some restriction in the fuel system causing the truck to starve for fuel til fuel pressure is built up completely in the entire system.

Drive-train shaking, engine sputtering, typically if I rev it up it'll smooth out. I've got a fuel filter in the garage, so I'll throw that on tonight.

 

[ASUMTNEER]

Changed the fuel filter tonight. Maybe it'll make a difference. Here's what came out.

 

[newtonmc49]

Your mechanic is right, blown head gasket or cracked head. Tore my heads off last week Sure enough, crack in the passenger side middle cylinder #3. My symptoms were rough idle at start up. I only had to put water in my overflow/reservoir once a year. No smoke, no over heating. But the longer you don't go out to start it the worse it would run until you cleaned out the water. Ended up thinking it did have a blown head gasket so I drove my truck for 2 weeks. Went to hope in my runner and it was damn near hydra locked. Pulled the plugs and shined a light down there and there you go.

Now I'm trying to figure out where to get a good head. Not that easy because I have all my cams and everything (valve lash) was set predict. So, just more work.

 

[newtonmc49]

Oh, I have probably drove like this for 3 solid years by the way. Slowly gets worse. Cracks were in the middle of the valves ports. Connecting the intake and exhaust ports.