which compression tester?
Discussion
Hi all
I have a thread going in the land rover sub forum as I think I hydrolocked my engine when off roading a while back. The advice seems to be to do a compression test first to try and identify the fault.
It's a 200tdi engine, so anyone have any thoughts on a good one to buy. Since I'm going to get one, it'd be good to get one I can use on other cars in the future, but I dont want to spend a fortune.
Failing that, anyone near leicester who wants to earn some beer tokens for doing a test for me?
I have a thread going in the land rover sub forum as I think I hydrolocked my engine when off roading a while back. The advice seems to be to do a compression test first to try and identify the fault.
It's a 200tdi engine, so anyone have any thoughts on a good one to buy. Since I'm going to get one, it'd be good to get one I can use on other cars in the future, but I dont want to spend a fortune.
Failing that, anyone near leicester who wants to earn some beer tokens for doing a test for me?
eltax91 said:
Thanks. Could you comment on the various fittings included in some kits? I'm a compression testing newbie so only know the basic principles!
Does a diesel one differ from a petrol one?
HugelyDoes a diesel one differ from a petrol one?
A petrol one screws into the spark plug
Diesels don't have sprakplugs so they go in the same hole as the injectors
And thats before you get to the peak pressures being totally different
To be honest i would whip the head off and measure the piston heights as a compression test will tell you very little about what shapes the rods are.
Its a piece of piss on a 200Tdi
And by the time you have the injectors out you are 25% of the way to getting the head off anyway
Edited by thinfourth2 on Friday 6th July 18:37
thinfourth2 said:
Hugely
A petrol one screws into the spark plug
Diesels don't have sprakplugs so they go in the same hole as the injectors
And thats before you get to the peak pressures being totally different
To be honest i would whip the head off and measure the piston heights as a compression test will tell you very little about what shapes the rods are.
Its a piece of piss on a 200Tdi
And by the time you have the injectors out you are 25% of the way to getting the head off anyway
Ah ok. So its not just a case of the same process, but using glow plug hole instead of spark plug hole? A petrol one screws into the spark plug
Diesels don't have sprakplugs so they go in the same hole as the injectors
And thats before you get to the peak pressures being totally different
To be honest i would whip the head off and measure the piston heights as a compression test will tell you very little about what shapes the rods are.
Its a piece of piss on a 200Tdi
And by the time you have the injectors out you are 25% of the way to getting the head off anyway
Edited by thinfourth2 on Friday 6th July 18:37
As for ripping it apart, I'm partly worried I have no idea what a 'good' engine looks like, so how can I diagnose a broken one! Also, I could fix what appears broken, reassemble and discover I missed something....
Might still tear it apart mind, can't make it worse!
eltax91 said:
Hi all
I have a thread going in the land rover sub forum as I think I hydrolocked my engine when off roading a while back. The advice seems to be to do a compression test first to try and identify the fault.
It's a 200tdi engine, so anyone have any thoughts on a good one to buy. Since I'm going to get one, it'd be good to get one I can use on other cars in the future, but I dont want to spend a fortune.
Failing that, anyone near leicester who wants to earn some beer tokens for doing a test for me?
You THINK you hydro'd your motor - well, what happened exactly? Can you expand?I have a thread going in the land rover sub forum as I think I hydrolocked my engine when off roading a while back. The advice seems to be to do a compression test first to try and identify the fault.
It's a 200tdi engine, so anyone have any thoughts on a good one to buy. Since I'm going to get one, it'd be good to get one I can use on other cars in the future, but I dont want to spend a fortune.
Failing that, anyone near leicester who wants to earn some beer tokens for doing a test for me?
I hydro'd my 4.0 Jeep Wrangler off-road once - symptoms were the engine dying instantly, and then when engaging the starter, it would not turn an inch - the motor was locked solid.
We pulled all 6 spark plugs (in the middle of Salisbury Plain
) and on cylinder no.1 (which had copped all the water) the spark plug was a b
h to remove - because as I turned it with the ratchet, it was pulling upwards against the cylinder full of water - hence like a 'reverse' hydraulic situation, with the plug trying to suck up water with it as it was removed.Once all the plugs were out - spinning the motor on the starter gave me fountains of water being sprayed out of the plug holes!
Once it was all out, replacing the plugs gave me a working engine again. However, it was definitely down on power. And after 6 months of further use, the (obviously bent when hydro-locked) con-rod on cylinder 1 snapped in half, writing off the entire motor...
Anyway with regard to your diesel - I would imagine if it had been properly hydro-locked, with the high compression of a diesel engine, you would have been stuck there, and it's likely the motor would have been properly written off immediately and never run again.
A friend drove a diesel Peugeot through a huge puddle recently - sucked up water, and killed it. Even after we'd removed the injectors and got the water out, it would not run - it was absolutely toast.
With regard to compression testers, as another poster said, I also have a Gunson unit that comes with two adaptors for spark plug holes - but I've no idea if it would fit a diesel injector hole. The display does go to over 200psi though, which should be enough to test a diesel engine.
But anyhow, like I said - give us some more info on what happened to yours?
Ray Luxury-Yacht said:
With regard to compression testers, as another poster said, I also have a Gunson unit that comes with two adaptors for spark plug holes - but I've no idea if it would fit a diesel injector hole. The display does go to over 200psi though, which should be enough to test a diesel engine.
I wouldn't chance it; most universal diesel compression testers go to around 800-1000psi.Ray Luxury-Yacht said:
You THINK you hydro'd your motor - well, what happened exactly? Can you expand?
I hydro'd my 4.0 Jeep Wrangler off-road once - symptoms were the engine dying instantly, and then when engaging the starter, it would not turn an inch - the motor was locked solid.
We pulled all 6 spark plugs (in the middle of Salisbury Plain ) and on cylinder no.1 (which had copped all the water) the spark plug was a bh to remove - because as I turned it with the ratchet, it was pulling upwards against the cylinder full of water - hence like a 'reverse' hydraulic situation, with the plug trying to suck up water with it as it was removed.
Once all the plugs were out - spinning the motor on the starter gave me fountains of water being sprayed out of the plug holes!
Once it was all out, replacing the plugs gave me a working engine again. However, it was definitely down on power. And after 6 months of further use, the (obviously bent when hydro-locked) con-rod on cylinder 1 snapped in half, writing off the entire motor...
Anyway with regard to your diesel - I would imagine if it had been properly hydro-locked, with the high compression of a diesel engine, you would have been stuck there, and it's likely the motor would have been properly written off immediately and never run again.
A friend drove a diesel Peugeot through a huge puddle recently - sucked up water, and killed it. Even after we'd removed the injectors and got the water out, it would not run - it was absolutely toast.
With regard to compression testers, as another poster said, I also have a Gunson unit that comes with two adaptors for spark plug holes - but I've no idea if it would fit a diesel injector hole. The display does go to over 200psi though, which should be enough to test a diesel engine.
But anyhow, like I said - give us some more info on what happened to yours?
Here you go: http://mobile.pistonheads.com/gassing/topic.asp?h=...I hydro'd my 4.0 Jeep Wrangler off-road once - symptoms were the engine dying instantly, and then when engaging the starter, it would not turn an inch - the motor was locked solid.
We pulled all 6 spark plugs (in the middle of Salisbury Plain
) and on cylinder no.1 (which had copped all the water) the spark plug was a bh to remove - because as I turned it with the ratchet, it was pulling upwards against the cylinder full of water - hence like a 'reverse' hydraulic situation, with the plug trying to suck up water with it as it was removed.Once all the plugs were out - spinning the motor on the starter gave me fountains of water being sprayed out of the plug holes!
Once it was all out, replacing the plugs gave me a working engine again. However, it was definitely down on power. And after 6 months of further use, the (obviously bent when hydro-locked) con-rod on cylinder 1 snapped in half, writing off the entire motor...
Anyway with regard to your diesel - I would imagine if it had been properly hydro-locked, with the high compression of a diesel engine, you would have been stuck there, and it's likely the motor would have been properly written off immediately and never run again.
A friend drove a diesel Peugeot through a huge puddle recently - sucked up water, and killed it. Even after we'd removed the injectors and got the water out, it would not run - it was absolutely toast.
With regard to compression testers, as another poster said, I also have a Gunson unit that comes with two adaptors for spark plug holes - but I've no idea if it would fit a diesel injector hole. The display does go to over 200psi though, which should be enough to test a diesel engine.
But anyhow, like I said - give us some more info on what happened to yours?
Ray Luxury-Yacht said:
With regard to compression testers, as another poster said, I also have a Gunson unit that comes with two adaptors for spark plug holes - but I've no idea if it would fit a diesel injector hole. The display does go to over 200psi though, which should be enough to test a diesel engine.
Nothing like enough; a healthy turbo diesel will typically generate 350-450psi on a compression check.eltax91 said:
Ah ok. So its not just a case of the same process, but using glow plug hole instead of spark plug hole?
As for ripping it apart, I'm partly worried I have no idea what a 'good' engine looks like, so how can I diagnose a broken one! Also, I could fix what appears broken, reassemble and discover I missed something....
Might still tear it apart mind, can't make it worse!
Getting the glow plugs out is probably the hardest bitAs for ripping it apart, I'm partly worried I have no idea what a 'good' engine looks like, so how can I diagnose a broken one! Also, I could fix what appears broken, reassemble and discover I missed something....
Might still tear it apart mind, can't make it worse!
And you don't look you measure
All the pistons at TDC will stick up above the block by a few mm (roughly) but they should all stick up exactly the same amount if one is lower then the other then its got a bent rod
Loads of guides online for doing a 200TDi head
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