5.7 GL Compression Test.... Also engine Alarm (Pics & Video

[stant1man]

I went to carry out a compression test tonight, grabbed hold of my spark plug socket wrench but it would not fit onto the plug as the manifold sits lower and makes it impossible.... is there a special tool to remove the plugs?

My oil pressure alarm is sounding constantly when the engine warms up and I cant get good power from my engine. I'm hoping it's just the oil pressure sender.... oil is clean as a whistle with no metal shards or grime...

I am hoping that if there was damage to rings that there would be evidence in the oil... I also hope that the power problem is ignition or fuel related... who knows :-S

 

[Don S]

Re: 5.7 GL Compression Test.... how do you get the plugs out? :-S

Re: 5.7 GL Compression Test.... how do you get the plugs out? :-S

Are you sure it's the oil pressure switch gone bad or could it be the temp switch
You really need to put the year of the engine so people have some clue what you have, even if it is a different engine.

For the spark plug socket, just make one like this..

One other note, use either the AC or NGK spark plug (Not Champion), they are shorter and won't be near as close to the manifolds.

 

[stant1man]

Re: 5.7 GL Compression Test.... how do you get the plugs out? :-S

Re: 5.7 GL Compression Test.... how do you get the plugs out? :-S

Are you sure it's the oil pressure switch gone bad or could it be the temp switch
You really need to put the year of the engine so people have some clue what you have, even if it is a different engine.

I really wish I could somehow better identify the year of the engine Don but there are no stickers or plates anywhere that help :-(

There is an oil pressure cylinder at the rear right which links to a gauge and I assume the warning alarm, temperature is really nice on the dash and you can happily hold your hand on the manifolds whilst she runs.

As the oil pressure gauge falls into the red the engine alarm starts to sound... if i rev her a little the alarm shuts off and the oil pressure picks up.

I am trying to find a good parts supplier locally but before spending any more money I need to replace this sender and compression check the engine... if it checks out i will start to work towards solving the running issues.

Thanks as always for your help and support Don.

Stan

 

[Don S]

Re: 5.7 GL Compression Test.... how do you get the plugs out? :-S

Re: 5.7 GL Compression Test.... how do you get the plugs out? :-S

The alarm switches are separate and different from the gauge senders.
Look around your engine. any senders (switches actually but look like senders) will have a tan/w black strip wire going to it.

 

[stant1man]

Re: 5.7 GL Compression Test.... how do you get the plugs out? :-S

Re: 5.7 GL Compression Test.... how do you get the plugs out? :-S

The alarm switches are separate and different from the gauge senders.
Look around your engine. any senders (switches actually but look like senders) will have a tan/w black strip wire going to it.

Well thats a worry... the gauge is reading low and the alarm is sounding... what are the chances of them both being faulty :-S

 

[Don S]

Re: 5.7 GL Compression Test.... how do you get the plugs out? :-S

Re: 5.7 GL Compression Test.... how do you get the plugs out? :-S

Hook up a mechanical gauge and check the oil pressure. Usually when an engine has low oil pressure, the lifters start rattling first.

Have you checked the engine oil? If it's over full, the oil could get foamy from the crankshaft hitting it, that would show as low oil pressure and poor running, and noisy lifters.

 

[stant1man]

Re: 5.7 GL Compression Test.... how do you get the plugs out? :-S

Re: 5.7 GL Compression Test.... how do you get the plugs out? :-S

Engine oil level is perfect, definately not getting whipped up. Lifters are relatively quiet... i'll see if I can take a video later today. Where can a mechanical gauge be connected?

 

[stant1man]

Re: 5.7 GL Compression Test.... how do you get the plugs out? :-S

Re: 5.7 GL Compression Test.... how do you get the plugs out? :-S

**Latest Update**

- New oil pressure sender arrived and has been installed.
- New distributer cap fitted as previous had green corrosion on the terminals
- New fuel filter installed as previous had dealt with water in fuel tank
- All plugs removed using a modified socket following Don's diagram above... thanks so much for this Don, it worked a treat.

Finally got compression test completed after wrestling with plugs that were rusted to the head.... they were very black and sooty, not wet or particularly oil fouled pic below>

I completed the compression test from cold as the plugs had not been removed by me at any time and it was the right thing to do... i broke two plugs trying to get them out and certainly could not have handled the heat whilst wrestling with them... I will get a further test completed once I have the new plugs....

Test result was as follows, feedback appreciated -

2 - 190psi
4 - 185psi
6 - 176psi
8 - 180psi

1 - 188psi
3 - 175psi
5 - 185psi
7 - 180psi

 

[Don S]

Re: 5.7 GL Compression Test.... how do you get the plugs out? :-S

Re: 5.7 GL Compression Test.... how do you get the plugs out? :-S

Hook up the mechanical gauge where the oil pressure sender is now. Remove sender, install you gauge.

Compression is not dependent on oil pressure.

 

[stant1man]

Re: 5.7 GL Compression Test.... how do you get the plugs out? :-S

Re: 5.7 GL Compression Test.... how do you get the plugs out? :-S

Hook up the mechanical gauge where the oil pressure sender is now. Remove sender, install you gauge.

Compression is not dependent on oil pressure.

I'll do it tomorrow Don, i'll need to find a gauge though. I was considering starting the engine to see if the alarms/low reading at dash was solved...

I will need new plugs since I broke two.... The plugs I removed are NGK BR6FS though im reading they should be BPR6EFS....can you shed any light?

 

[stant1man]

Re: 5.7 GL Compression Test.... how do you get the plugs out? :-S

Re: 5.7 GL Compression Test.... how do you get the plugs out? :-S

these perhaps?

http://www.ebay.co.uk/itm/Spark-Plu...at_Engines_EngineParts_SM&hash=item2eb4f7a2be

 

[Don S]

Re: 5.7 GL Compression Test.... how do you get the plugs out? :-S

Re: 5.7 GL Compression Test.... how do you get the plugs out? :-S

I will need new plugs since I broke two.... The plugs I removed are NGK BR6FS though im reading they should be BPR6EFS....can you shed any light?

That engine did take the BPR6EFS plugs from the factory, unless they put the wrong heads on your long block.
Easy to check, just look at them and see if they are long or short threads in the head. Think digital camera if you can't get in there to look.

 

[stant1man]

Re: 5.7 GL Compression Test.... how do you get the plugs out? :-S

Re: 5.7 GL Compression Test.... how do you get the plugs out? :-S

Good tip Don, I hope this is another area where an improvement can be made

 

[stant1man]

Re: 5.7 GL Compression Test.... how do you get the plugs out? :-S

Re: 5.7 GL Compression Test.... how do you get the plugs out? :-S

Looks like a shallow thread to me... what do you guys think?

 

[stant1man]

Re: 5.7 GL Compression Test.... how do you get the plugs out? :-S

Re: 5.7 GL Compression Test.... how do you get the plugs out? :-S

Fitted the new plugs tonight and ran the engine for the first time since fitting the new oil pressure sender.... gauge no longer in the red and once warm the gaugue dropped a little but certainly not by much and nowhere near the red on the dash... great news i thought but soon after the engine alarm starts to sound. I have taken a video to show what has been happening. Could I also have a faulty oil pressure switch.

http://youtu.be/Iexn0Ew1f9k


I also noticed that my engine never seems to get up to temperature so I pulled the thermostat housing...Found this... housing was empty... i presume a thermostat belongs here....

 

[Don S]

Re: 5.7 GL Compression Test.... how do you get the plugs out? :-S

Re: 5.7 GL Compression Test.... how do you get the plugs out? :-S

Those pictues of the spark plug hole threads are really hard to tell. So straight on there is no dept perception.
The top one does look a little like short threads though.

If you put the long plugs in it and ran it, pull them out and see if the threads are starting to turn black due to being past the theads of the head.

 

[stant1man]

Re: 5.7 GL Compression Test.... how do you get the plugs out? :-S

Re: 5.7 GL Compression Test.... how do you get the plugs out? :-S

Definately short threads Don... I replaced like for like.... what do you think of my new developments?

 

[Don S]

Re: 5.7 GL Compression Test.... how do you get the plugs out? :-S

Re: 5.7 GL Compression Test.... how do you get the plugs out? :-S

Remove the wire from the oil pressure switch and see if the alarm stops. Did you ever put a mechanical gauge on it?

 

[stant1man]

Re: 5.7 GL Compression Test.... how do you get the plugs out? :-S

Re: 5.7 GL Compression Test.... how do you get the plugs out? :-S

I couldn't get a mechanical gauge... would need to order one and it would take days to arrive... feeling a little more reassured now that my dash is reading what seems to be normal.

Where is the little blighter so I can take the wire off and see if I have some peace from the dam beeping lol....

Also any idea what thermostat I need, I can clean up the housing im sure... Presumably it's held in with a circlip of sorts?

 

[Don S]

Re: 5.7 GL Compression Test.... how do you get the plugs out? :-S

Re: 5.7 GL Compression Test.... how do you get the plugs out? :-S

I don't know where it's at for sure, may be above the oil filter housing on the block, or by the distributor.
It may even be the alarm switch for the cooling system causing the trouble. Take it off to, should find it around the thermostat housing.