1HZ Compression - Advice?? (1 Viewer)

[Entaran]

Well, the verdict is back.

The engine is 17 days and 6700 km out of warranty from the engine rebuilder (who sounded dodgy). I didn't pay for the rebuild but I do have the receipts (6000 dollars worth).

It appears the pistons/rods/bearings are all about 66700 kms old.

However, contrary to what it SHOULD BE, (385psi - 525psi or 2650kpa - 3620kpa)

1: 2413kpa (350psi)
2: 2137kpa (310psi)
3: 2068kpa (300psi)
4: 2068kpa (300psi)
5: 2068kpa (300psi)
6: 2137kpa (310psi)

There is a very very small exhaust manifold leak (I'm not sure if this affects this).

Can I fix the compression without completing a full and complete rebuild? Is it just a case of rings and a new headgasket? Is there any way to help the issue or is it terminal?

Also, the car still feels great to drive, it has tons of grunt and doesn't appear to have any power loss versus a known good 1hz 75 series ute. Obviously, this puts a damper on my turbo ideas, but I'm still interested in knowing what the "fix" is.

Cheers in advance,
Entaran

 

[roscoFJ73]

Thats bad news and dodgy engine rebuilders should be shot.

A full rebuild kit cost about $1100,then you have machining and assembly costs.
I would drive it gently for a while,save your money and if you feel up to it attempt a full rebuild yourself or with the help of your mechanic mate.
Pulling it apart just to do the rings will be a lot of effort that wont last in the long term and you will end up back where you are now within a year or 2.
Do it right ,do it once.

One more thing ,maybe its a valve problem. If the bottom end is genuinly 67000 klms old then it should be good but not if it wasnt rebored.
Try the rebuilder again with a friend as witness and ask him face to face what exactly did he do.
You may shame him into helping you out

 

[Greg_B]

I am really sorry to hear this Entaran.

roscoFJ73 give good advice.

I agree: Save up, make a plan, do it once.

gb

 

[crushers]

wrong head gasket could equal dropped the compression figures?

the compression is very low but it is even across the board which doesn't usually happen. i would suspect a wrong part was used somewhere...
there is no way the compression should have dropped evenly and that quickly...

 

[Entaran]

Could someone tell me how to do a compression test on a diesel? Preferably a safe way?

I know the mechanic would probably have done it correctly, but something seems amiss and i've never used this mechanic before (although heaps of guys here in ballarat swear by him). A short step by step guide? ... i'm sure there's a link on here somewhere, could someone give me a helping hand?

 

[Greg_B]

1) Do a valve set cold.

2) Run up to op temp

3) pop off fuel solinoid connection so fuel stays off

4) remove glow plugs

5) install compression tester in 1st hole

6) crank over till comp gauge stops moving

7) release pressure, repeat 5 and 6 for each cylinder

That is real quick as I am out the door for the weekend. If I forget anything people will catch and add.

You could do a cold comp test too, and see the difference between the two.

hth's

gb

 

[mac]

I think on most you also hold the accelerator pedal down.

 

[mac]

Here ya go straight from the FSM.
As Greg stated but in addition hold the accelerator open and make sure your battery is sufficient to crank @250rpm or more.
#'s should be 526PSI and a min. of 384PSI.
If the #'s read low after that then try putting a small amount of oil in the glow plug hole and test again. If the #'s come up you may have a ring problem. If they stay low it's likely a valve that's not seating.
Let us know what you find.
Peter

 

[Entaran]

I'll probably get around to it sometime this week. I'm investigating what crushers said.

 

[Entaran]

Compression is as stated. Oil didn't do a thing. Car doesn't blow large amounts of smoke and doesn't use oil (at any form of alarming rate.) Every diesel i've ever been near has used oil at a rate of about a litre per 5000 or so km. Being that the sump is like 9 litres, I don't see this being an issue.

I'm going to speak to the mechanic that looked at my car about it possibly being the wrong headgasket (IE: Wrong compression ratios in the block... HG too thin)

 

[crushers]

this is actually good news...
i am really thinking wrong head gasket...

 

[mac]

Yeah, strange. For it to be valve related, ALL of the valves would not be seating properly. Unlikely unless they were all adjusted incorrectly at rebuild time.

 

[Tapage]

Yeah, strange. For it to be valve related, ALL of the valves would not be seating properly. Unlikely unless they were all adjusted incorrectly at rebuild time.

I'm with you .. and thing a little bit about the valves .. the idle speed is normal .?

 

[roscoFJ73]

Yeah, well he did mention a engine rebuilder sounding dodgy in the original post.
Maybe they got the wrong shims in there.

 

[nickw]

I'm going to speak to the mechanic that looked at my car about it possibly being the wrong headgasket (IE: Wrong compression ratios in the block... HG too thin)

Wouldn't it be too thick if the compression was dropping?
Thiner would raise the compression.

Maybe he just used he worng HG as you said.
You could always order the proper headgasket and replace it.

Maybe he put the wrong pistons in?
Do you have a recipt with what he did?

Cheers,
Nick

 

[mac]

Wouldn't it be too thick if the compression was dropping?
Thiner would raise the compression.

Maybe he just used he worng HG as you said.
You could always order the proper headgasket and replace it.

Maybe he put the wrong pistons in?
Do you have a recipt with what he did?

Cheers,
Nick

OOOOH, 1HDT pistons? Not likely. What are the odds? I wonder if it would even run, though? Nah, he would need the conrods too...

 

[crushers]

or...
i had an unusual one a while back. the symtoms were:

even numbers across the board but compression was low.
it started okay but blew black at cold start, fine when warm,
power was low and the engine was gutless...

when the head was pulled the prechambers never had been installed...

go figure.

 

[nickw]

OOOOH, 1HDT pistons? Not likely. What are the odds? I wonder if it would even run, though? Nah, he would need the conrods too...

Do I sense a wee bit of exciment?
Something tells me you would love to get yours hand on his pistons if they were 1HD-T's.

 

[bigbrowndog]

it might pay to check it with a different compression gauge.

 

[nickw]

it might pay to check it with a different compression gauge.

That is an EXCELLENT idea.