turbocharged 3B failure/high EGT's/Abuse? (1 Viewer)

[robmobile73]

My 3B has failed. Short history:
BJ73 overheated on the drive home after purchase(previous mechanic/owner fixed rusted out freeze plug with JB weld which blew out on the highway)..Engine swallowed piece of exhaust valve seat on 2 cylinders scaring the piston dome, but not the bore.

replaced head and smoothed out piston top divits with a small grinder.

Engine ran fine, but decided to turbo for increased power. Had blowby with turbo but got it mostly sorted out. Had good power and EGT's acceptable on level ground on highway. long hills at 90K or medium grades at 110K (with 32" tires and 2" lift) would cause EGT's to head north of 700C and have to slow down. Boost could reach 15PSI uphill.

On a 45min drive at 110K with ambient temp at 90+ degrees on a long uphill the EGT's spiked over 700 for perhaps 20-30seconds before I noticed. After this she was down on power and down to 3cylinders 15 min later when I got home.

No oil in water no water in oil. Compression test numbers 410, 470, 80, 410..........Dropped pan, removed head, removed pistons.......... 2cnd ring broken on 1, 2, and 3. 1st ring on #3 is stuck which in addition to 2cnd ring breakage caused the piston to scrape and wear instead of staying centered. 3 piston crowns are eroded/melted/burned away around the edge between the valve seat indentions.

Crank rod journals are smooth. Will try a "in frame rebuild" new pistons, rings, rod bearings...If I can hone out the minor scoring of #3 bore. If it's too deep I'll have to pull the engine and get it rebored.

There are multiple choices for standard pistons available, mark1-1 mark 2 mark 3 etc. I have looked through the engine manual I have, and haven't found anything in the section on pistons that explains the markings. (or says anything about it for that matter). Under the pistons inside the skirt mine are marked ART _3 on one side and 530850 on the other.

I am considering doing a ceramic heat reflective piston dome coating(cerakote) on the new pistons. Snorkel to get cooler air, ditching the watercooling on the turbo to reduce water temperature, and moving the AC condenser further from the radiator to prevent heat soaking between it and the radiator(current gap is less than .5").

Anyone seen this type of damage before from EGT's, boost, overheat,....Or have any advice on exactly what manual explains the piston markings? The manual I am using is:

 

[OGBeno]

 

[robmobile73]

Thanks Onur. I was still looking at pistons for some strange katakana or kanji or something.....I'll get it figured out. I remember this page on the manual I downloaded, I just didn't read it close enough to know the "Mark" was in the measurement. I'll get on it tomorrow. I just hope after I clean up the cylinder with some degreaser and steel wool that it's not scored too badly.

 

[FJBen]

How many KM's did the 3B have when you bought it? What was the condition of the 3B when you bought it? Rusted freeze plug sounds like cooling system is not up to snuff, which is 100% not surprising. Probably needs radiator re-done or new, heater core cleaned out, all hoses, water pump and block flushed/cleaned.


Then, you are pushing a turbo hard on an engine that was never intended to be turbo'd....on an engine with unknown history, up to speeds/hills almost 70, with larger tires you could be doing faster than you think, in 90+ ambient temps with A/C on.

Personally, I'm not surprised. You are working that little 3B.


I wouldn't do an in frame rebuild if it were me. I had the chance and chose to pull it and re-do it. This is the second time you've have a major failure, seems like it's time to pull it out and do it right from the ground up so you know what you have going on.



Is you EGT probe pre or post turbo?

 

[robmobile73]

How many KM's did the 3B have when you bought it? What was the condition of the 3B when you bought it? Rusted freeze plug sounds like cooling system is not up to snuff, which is 100% not surprising. Probably needs radiator re-done or new, heater core cleaned out, all hoses, water pump and block flushed/cleaned.


Then, you are pushing a turbo hard on an engine that was never intended to be turbo'd....on an engine with unknown history, up to speeds/hills almost 70, with larger tires you could be doing faster than you think, in 90+ ambient temps with A/C on.

Personally, I'm not surprised. You are working that little 3B.


I wouldn't do an in frame rebuild if it were me. I had the chance and chose to pull it and re-do it. This is the second time you've have a major failure, seems like it's time to pull it out and do it right from the ground up so you know what you have going on.



Is you EGT probe pre or post turbo?

EGT is pre turbo.

Cooling system was shot when I bought it. 250000KM and from Spain. Warm country they don't use antifreeze much so cooling systems rot and freeze plugs rust. The head cracked on the 90 mile drive to my second home 3 days after I bought the vehicle. I didn't see all these things when I bought it. I put in a new radiator and removed the entire factory heat/vent system(heater core bad, vents broken, cable rusted, plastic control arms broken etc...shot..) and installed a vintage air system. New hoses and block flushed 3 or 4 times after new head install.

I know I was pushing it hard. I had my eye on the temp guage and the EGT's, but on the particular hill I was preoccupied by a distraction and didn't realize the EGT's had built up that much....This day was my second highway trip at 65mph + in warm weather. I was still trying to sort things out in the tuning/fueling. I calculated for tire diameter. 110K on the dash is right at 69-70mph on my gps.

We'll see on the rebuild. Bearing surfaces are smooth and good and I have no reason to believe anything else is bad, or would be worn out at this mileage...........I should have replaced the pistons at the time of the head replacement. The stuck ring on #3 seams to be caused by melting/eroding of the piston on the spot where one of the previous damage points on the crown was located downard to the point where the top ring was "pinched/stuck". With a broken second ring there was then almost no compression on that piston and piston slap..........I am not sure what would cause #2 ring to break on cylinders 1,2, and 3. Unless it happened in the previous overheat incident(do rings break on overheat??) Originally I was not going to turbo, but when I saw how cheap turbochargers had gotten and looked at the cost/work of adding a turbo vs. the cost of re-gearing to run the tires I wanted I decided to turbo. ................................I'm not "in love with the 3B". The 70 is underpowered with the 3B for modern American highways. I was satisfied with the power I have after the turbo, but my previously damaged pistons didn't hold up long enough for me to get EGT's sorted out. I do not want this engine enough to go through the time and effort of a multi thousand $ rebuild. If the bores aren't scored to bad I can rering/new pistons, and get it back on the road for awhile. If it breaks again I'll ditch the 3B for something more powerful/durable.....................I once swapped a cummins 4BT into a 1/2 ton chevy and had it running and driving in 17 hours flat. I don't see that happening with the BJ73 or I'd do it again. Not enough room and driveline won't bolt up.

 

[GTSSportCoupe]

Can you post some pictures of what you're describing?

If I was you, I would not bother fixing that 3B. Sell the good parts, and put the money toward a 13BT. Direct Injection, and an engine designed for turbo. No more head problems, no more heat problems. I bet the end cost will be about the same as rebuilding the 3B.

 

[FJBen]

Not sure I would rebuild a 3B at this point. Totally agree with @GTSSportCoupe if you want some power to climb hills, keep up with traffic ditch the 3B, it's already given you fits and needs rebuilt. You could try your luck again with rings/pistons in frame and see what happens I suppose, but that could be throwing good money after bad.

You can get adapters for 4BT to H55f...plus you already did it in another vehicle. Probably will have to lift it more.Slap it in and be done and the only thing you have to worry about is the fillings rattling out of your teeth.

A 13BT would be sweet, but they are harder to find and they aren't cheap.

Look at the Isuzu 4BDT as well. A little more refined than the 4BT. Again you will probably have to have more lift for either of these swaps.

 

[Dougal]

700C doesn't melt anything. I have seen north of 900C with no damage on my DI Isuzu (I've had those pistons out) Also IDI engines don't melt pistons very easily.

Were your pistons alfin type with reinforced ring-lands? If not then that is the likely root cause of your failure. Too much boost on a high compression engine with weak pistons.

 

[OGBeno]

I believe his pistons were factory Toyota (ART).

 

[robmobile73]

Can you post some pictures of what you're describing?

If I was you, I would not bother fixing that 3B. Sell the good parts, and put the money toward a 13BT. Direct Injection, and an engine designed for turbo. No more head problems, no more heat problems. I bet the end cost will be about the same as rebuilding the 3B.

Not sure I would rebuild a 3B at this point. Totally agree with @GTSSportCoupe if you want some power to climb hills, keep up with traffic ditch the 3B, it's already given you fits and needs rebuilt. You could try your luck again with rings/pistons in frame and see what happens I suppose, but that could be throwing good money after bad.

You can get adapters for 4BT to H55f...plus you already did it in another vehicle. Probably will have to lift it more.Slap it in and be done and the only thing you have to worry about is the fillings rattling out of your teeth.

A 13BT would be sweet, but they are harder to find and they aren't cheap.

Look at the Isuzu 4BDT as well. A little more refined than the 4BT. Again you will probably have to have more lift for either of these swaps.

The 4BT convert I did worked well as I found a 4bta120 still in a bread truck running 2 hours away for $1700. It was in a 71 chevy. I got the noise down with massive amounts of insulation that would make a new mercedes lookbad, but the rattling was too much. Every forum I read tells me it takes 5" lift to clear the pan. I have 2.5-3" now and could surely cut/weld/modify a oil pan.................I'm not really fond of the Idea of spending 4K+for a non rebuilt used old toyota diesel.
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700C doesn't melt anything. I have seen north of 900C with no damage on my DI Isuzu (I've had those pistons out) Also IDI engines don't melt pistons very easily.

Were your pistons alfin type with reinforced ring-lands? If not then that is the likely root cause of your failure. Too much boost on a high compression engine with weak pistons.

Pistons are stamped art. here's a picture showing some erosion of the crown between the valve seats on the left is a not so eroded piston on the right is eroded all four are eroded with three of them eroded more than one.

 

[OGBeno]

ART is the Toyota piston manufacturer.

 

[robmobile73]

The worst bore and the worst piston that had the stuck ring. I don't think I can hone out that deep scratch but I may try.
I'm sort of treating this truck as a learning tool for me. I've done a few things for the first time and quite a lot of things I haven't done in a long time with this vehicle.......earlier today I was researching how to fabricate a cylinder sleeve removal tool out of threaded rod and some steel plate. It didn't look all that difficult... Tonight I'm a bit disappointed as I don't see anything for a cylinder sleeve removal tool to grip on. It's as if the bottom of the sleeve bottoms out into the block. You cannot push or pull up on the bottom of the sleeve with anything. Do they weld a puller attachment to the bore to extract the liners?

 

[Dougal]

That piston does look cooked. What was the oil condition? Any chance that squirter is blocked?

 

[robmobile73]

That piston does look cooked. What was the oil condition? Any chance that squirter is blocked?

No clue on the oil squirter other than the hole in the end looks clear.

Keep in mind 700-750C from a pre turbo temp probe in my 1/8 wall welded exhaust manifold is likely much lower than the temps inside the combustion chamber.

There was a previous brutal overheat that lead to head replacement....Coolant blew out of a JB weld freeze plug(previous owner/mechanic) and water was no longer in contact with temp guage probe so the guage didn't go hot. She started slowing down on the highway Pushed in the clutch to pull over and it locked up with that lousy brown smoke out of the exhaust..............Replaced the head, 2 pistons were scarred, but not punctured and the bores were still go so I left them in but smoothed the sharp edges and high spots on the domes. Those were weak at that point.

I believe it suffered overheat prior to my owning the vehicle. Evidence of head replacement present. The head on the vehicle when I bought it had mismatched valves that were too large for the valve seats. Valves literally seated on the shoulder of the valve Flat on angle edge, due to nothing more than spring pressure. No way toyota put it out of the factory like that. It ran that way evidently, but the guy at the head shop said he had never seen anything like that in 20 years of doing head work.

.....................Oil level has not gone below the "cross hatch" on the dipstick. Meaning never less than 2 quarts from full since I've had it. Engine temp guage went as high as 3/4 of the way from L to H. Normally it runs at about 3-4/10 of the way L to H.

Time is important to me right now. I'm leaning toward trying to hone out the scuffs on the cylinders a new set of pistons , rings, rod bearings and reassembling. Even if the bores are imperfect I think it will hold up and run for some time. As jacked as it was I had over 400PSI compression on every cylinder except the one with the stuck ring. Reducing fuel and avoiding the interstate while enjoying some local 4wheeling, beach camping, etc... add towing and rental car to my insurance policy. If the engine lets go again That will be it for the 3B and me.

I'd kind of like to do a old school DIY cylinder liner replacement just for the learning experience, but when I crawled underneath to look at the bottom of the engine today the liners do not protrude. The block casting covers the bottom of the liners. I don't know how you get anything under the liner bottom to push or pull it out. Toyota has a Special Service tool for this, but looking at the bottom of the engine I have no Idea how you'd use it.....If I could see the liner walls protruding down and a way to insert the tool between the block and liner I'd understand, but I'm not seeing anything like that.

When I think about lost time I see 3B rebuild as 1 month+, in frame rebuild 10 days, "easy engine swap(something fits in easily and readily bolts up with available adapter)"4-6 weeks, "developmental engine swap(something big requiring clearancing and modfication of driveline/custom adapter plates)" 2+months.

 

[mjosoba]

What about a 14 or 15BT? They’re easier to find than a good 13bt.

 

[mjosoba]

Edit: Double post

 

[robmobile73]

What about a 14 or 15BT? They’re easier to find than a good 13bt.

I agree with you they are easier to find as they are/were used much more recently in the short Toyota buses......Still however it's coming in from overseas. There was a post on these forums not too long ago from someone offering 14 or 15BT's used running pullouts from Japan for $4500 FOB. Somewhere else I read there are some differences with bellhousings/flywheels(don't remember details). I don't think its a straight bolt in replacement.

 

[mjosoba]

@robmobile73 Im refinishing my floors today, wife project smh, or I’d do more digging. But I’m fairly sure the engine mounts are the same, and I think I’ve seen several threads where the OP put one in various LC’s with an H55. Maybe an A440 as well. I think you had to have the right H55 bellhousing, and input shaft, from a 2H H55 (maybe?). But I think it’s pretty straight forward. I think that would be nearly your cheapest route, aside from a used 3b or 13bt.

 

[Dougal]

No clue on the oil squirter other than the hole in the end looks clear.

Keep in mind 700-750C from a pre turbo temp probe in my 1/8 wall welded exhaust manifold is likely much lower than the temps inside the combustion chamber.

There was a previous brutal overheat that lead to head replacement....Coolant blew out of a JB weld freeze plug(previous owner/mechanic) and water was no longer in contact with temp guage probe so the guage didn't go hot. She started slowing down on the highway Pushed in the clutch to pull over and it locked up with that lousy brown smoke out of the exhaust..............Replaced the head, 2 pistons were scarred, but not punctured and the bores were still go so I left them in but smoothed the sharp edges and high spots on the domes. Those were weak at that point.

I believe it suffered overheat prior to my owning the vehicle. Evidence of head replacement present. The head on the vehicle when I bought it had mismatched valves that were too large for the valve seats. Valves literally seated on the shoulder of the valve Flat on angle edge, due to nothing more than spring pressure. No way toyota put it out of the factory like that. It ran that way evidently, but the guy at the head shop said he had never seen anything like that in 20 years of doing head work.

.....................Oil level has not gone below the "cross hatch" on the dipstick. Meaning never less than 2 quarts from full since I've had it. Engine temp guage went as high as 3/4 of the way from L to H. Normally it runs at about 3-4/10 of the way L to H.

Time is important to me right now. I'm leaning toward trying to hone out the scuffs on the cylinders a new set of pistons , rings, rod bearings and reassembling. Even if the bores are imperfect I think it will hold up and run for some time. As jacked as it was I had over 400PSI compression on every cylinder except the one with the stuck ring. Reducing fuel and avoiding the interstate while enjoying some local 4wheeling, beach camping, etc... add towing and rental car to my insurance policy. If the engine lets go again That will be it for the 3B and me.

I'd kind of like to do a old school DIY cylinder liner replacement just for the learning experience, but when I crawled underneath to look at the bottom of the engine today the liners do not protrude. The block casting covers the bottom of the liners. I don't know how you get anything under the liner bottom to push or pull it out. Toyota has a Special Service tool for this, but looking at the bottom of the engine I have no Idea how you'd use it.....If I could see the liner walls protruding down and a way to insert the tool between the block and liner I'd understand, but I'm not seeing anything like that.

When I think about lost time I see 3B rebuild as 1 month+, in frame rebuild 10 days, "easy engine swap(something fits in easily and readily bolts up with available adapter)"4-6 weeks, "developmental engine swap(something big requiring clearancing and modfication of driveline/custom adapter plates)" 2+months.

Could there be a valve problem that mostly cut air-flow in or out of that cylinder? Something caused a local overheat and it's just the one. 700C pre-turbo doesn't hurt anything if it's a true measurement and all cylinders are even. But if you had one at 950C and the others at 500C you'd have a problem and not pick it.

 

[FJBen]

Any shop that has a 102mm sleeve tool can do this.
I had one machined out of aluminum I can send your way for shipping price if you want to use it.

I thought you would have to pull the crank and oil squirters to get a good enough pull on it. Maybe not the crank though. It’s threaded and fits the sleeve perfect so you can make a threaded rod puller and pull them out.