Rebuilt 1HD-T engine blowby when hot

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Hi, so I just rebuilt my 1hd-t engine completely because of bad compression and excessive blow by, everything brand new.
All the head was worked and all valves and valve guides were replaced with OEM.
Engine was std, so instead of oversizing the pistons the shop used new Cylinder Sleeves and I bought std forged pistons with OEM std rings.
The crankshaft was machined from std to .10 with with brand new bearings.

The engine has around 4000KMs, I just made a long trip (200KMs) and when I got home I noticed blowby from the breather then I opened the oil cap and found that the blow by was too much...

I have used DELO 400 LE 15w40, with change intervals of 500KMs, 1500KMs, 3000KM, each of it with their respective oil filter change.

There is blow by only when the engine is hot, if I turn the car on when cold it does not presents any blow by. Any idea of what can be happening? Should I switch to 20w50?

Here is a video of it:


Rob.
 

GTSSportCoupe

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Looks like the rings may not have seated properly. Did you consider running a Break-In Oil (no friction modifiers)? The oil you used might have been too good to allow the rings to seat right. Maybe talk to the machine shop who did your engine work and ask them about it. Maybe if you ran something like this for a while it would solve the problem: Diesel Break-In Oil 15W-40 - Products
 

Locked79

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Before you tear it apart again, really load up the engine, varying rpm and speed. Looks like the break in may have been too gentle. Tow a trailer through the mountains or up a hill, get those rings to bed in. 3 oil changes in 3000km is way too pedantic. My new 2017 cruiser didn't get its first oil change till 10000km.

Have a read of this. Gives you an idea of how long you've got to break it in properly.
www.mototuneusa.com/break_in_secrets.htm
 
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Before you tear it apart again, really load up the engine, varying rpm and speed. Looks like the break in may have been too gentle. Tow a trailer through the mountains or up a hill, get those rings to bed in. 3 oil changes in 3000km is way too pedantic. My new 2017 cruiser didn't get its first oil change till 10000km.

Have a read of this. Gives you an idea of how long you've got to break it in properly.
www.mototuneusa.com/break_in_secrets.htm

Exact thing happened after a 2h rebuild, put a 2500lb travel trailer behind it and covered the rad and ran a steep hill twice and it then seated the rings in.
 
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Should I re-ring again?
If you only have 4000km on it, it's probably not had a good chance to be run in.
Load it up, or two a loaded trailer through the mountains. Drive it like you stole it for the next 4000km, and see what happens. Babying it now is not doing it any favours.

Edit, I see the other guys beat me to it.

Blow by, or oil use is a common complaint on rebuilt 1HD-T, FT etc, nearly always seems like people treat them like they are made from glass
 
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Thanks guys, I thought revving it several times on the highway was supposed to make the job, but it did not.
I will try to tow something up hill and check.
 

roscoFJ73

 
 
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The RPMs seem to rising and falling.

There is blow by only when the engine is hot, if I turn the car on when cold it does not presents any blow by. Any idea of what can be happening? Should I switch to 20w50?
When an engine starts up cold, the gap between the rings and bore is tight. As it heats up the bore expands slightly more than the piston.
What concerns me is that maybe the gap is too much when warmed up causing the blow by.
But for the time being I would treat it as the rings not being seated.

When I started my 1HZ after a rebuild , I took the rpms up to 4000 for a second or so then varied the rpms by using different gears on the freeway for the next few thousand klms
My temp factory temp gauge climbed to 3mm off the red for a short period, you could really feel the hot glow. But it went normal after about 1500klms.
It felt like it gained full power at about 10000klms.
 
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Also, engine compression braking is supposed to seat rings well. On a couple of new turbo VWs (that can be known to burn oil) I bought with manual transmissions, when new I ran them repeatedly up to 100mph and then decelerated using engine braking. They turned out to be tight engines with no oil burn problems.
 
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No success, apparently my oil pump is not supplying enough pressure and my rings just got stuck into the piston (no expansion) and that is creating the problem.

I need some help getting the part numbers for the oil pump rebuild.
 
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I'll need to replace rings, bearings and valve seals as far as I know, and the oil pump of course.
 

Locked79

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No success, apparently my oil pump is not supplying enough pressure and my rings just got stuck into the piston (no expansion) and that is creating the problem.

I need some help getting the part numbers for the oil pump rebuild.
Do you have oil pressure numbers that you can share? I can help with part numbers. What year is your vehicle.

Another thing that caught my eye, you say the engine was resleeved. The 1hdt is a parent bore block. Why would you add sleeves instead of going .25mm oversize.
 
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The engine block had a small crack on one of the cylinders, very small, I had the same problem on my B engine and I just re-sleeved and it has been running for more than 300K KMs without an issue.

Its a 96 HDJ80 land cruiser, according to toyodiy this is my code:

upload_2018-2-8_10-19-48.png

ToyoDIY.com

But no idea what are parts for the pil pump.
 

roscoFJ73

 
 
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Basically the FSM outlines 3 points to measure wear in the oil pump and if any are outside the specs, it says to replace the oil pump assembly.
This means the driven rotor and housing.
I'm not sure if you could mix new and old parts safely.
The Australian online sellers all seem to want to sell the timing gear case with it for about $950AUD genuine
 
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I'll need to replace rings, bearings and valve seals as far as I know, and the oil pump of course.

Seen this same problem with a fellow cruiser head in Vancouver Bc, he recieved a complete short block from Toyota that I ordered for him from New Zealand. He built the engine and could hear a noise from the engine, finally after months of trouble shooting he figure out it was his oil pump...

Should be standard service on rebuild to put in a new pump gears and measure as per FSM, good luck and sorry for the bad news.
 
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I will take a measure of the Engine oil pressure first to take note of the numbers.
Then I will replace my pressure relief valve and check again the pressure.

I'll follow the engine's manual as it says:

upload_2018-2-8_16-56-50.png


http://www.trollholescruisers.com/Tech/Manuals/Engine/1990 1HD_1HZ_1PZ-T FSM.pdf

1*No Oil Leak.
2*Relief Valve faulty (?)
3*Oil Pump faulty (?) < I recall that the oil pump gears had not wear.
4*DELO 400 LE 15w40.
5*Crankshaft bearings are new.
6*Connecting Rods bearings are new.
7*Oil filter is new.

I will replace my Relief Valve and check oil pressure again, I hope is that.
 
Last edited:
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Some progress today.




I am taking the engine down by myself to save money. I eventually will take it to my mechanbic, I prefer to have a specialist working on this.
I will delay some time to save money in case of oil pump replacement. I will get back to this in a while.

Thanks for the comments.
 
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