low compression 60 150 150 150 please help

[Turbizmo]

ok Well I did a compression test on my car and these where the numbers 60 150 150 150. I have 8 to something pistons and eagle rods Stock valves and springs the headgasket its some what new around 5k well my question is. Is it a Piston Ring A burned valve a BHG or what. If its a ring is there any easier way to put new ones than to take down the whole motor?The car does not over heat I use it as a commuter. It trows little smoke out the breather and a little out the exhaust. any ideas ### help.

 

[CODE4]

Could be any of the things you mentioned. If it is in fact a bad ring, the correct way is to tear it down, check for taper & out of round, bore/hone as necessary, and install new rings. Anything less is your call and potentially a waste of money if it fails soon after.

A bad head gasket will show symptoms of bubbles in the coolant during a compression test or cross contamination of fluids.

 

[Locke]

Leak down test.

 

[#40Fan]

Pour a little oil down the low cylinder spark plug hole and retest. Post results. Just a little oil, about a half of a cap full.

 

[Boosted_talon98]

60 sounds alittle high for a ring... I guess anything is possible but my ring was throwing 15-20... What made you do a comp test? Def do a leakdown test

 

[hostile]

Do a leakdown test, it might be a valve.

 

[Turbizmo]

I didn't want to say whats a leak down test before i did some research but all I can find is that everyone says go to shop and get it done for about 80 bucks. so I guess I have to say whats Leak down test? I will had oil to the low compression piston and put the results later on today thanks.

 

[Calan]

I didn't want to say whats a leak down test before i did some research but all I can find is that everyone says go to shop and get it done for about 80 bucks. so I guess I have to say whats Leak down test? I will had oil to the low compression piston and put the results later on today thanks.

I'm guessing your search button must be messed up then.

Compression and Leak-Down Testing

 

[Turbizmo]

Ok well i did another compression test here are the results when the engine was cold from left to right

1: 60. then when oil added it was 90.

2: 150. then when oil added it was 180.

3:150. then when oil added it was 180.

4:150. then when oil added it was 180.

Then when engine was warm:

1: 60. Then when oil added it was 95

2.3.and 4. all stayed the same.

so any ideas?

 

[Calan]

so any ideas?

Yeah... do a leak-down test like 3 other people suggested.

 

[Turbizmo]

i will buy me the leak tester today and post the results thanks

Ok one question if its in fact my piston rings since i forgot what pitons size are theyi found a peper from what i keep from the pistons and this what its says BORE 3.464 (87.99mm) so will these rings work im assuming my pistons are 8.8:1 part number 208476


ok so i droped my car at my friends shop and they told me indeed it was the pistons rings so my question is can i use these rings >>>

CP Piston Rings kit 88mm Honda 420a 300zx ford mitsu: eBay Motors (item 350299630112 end time Jul-29-10 10:13:53 PDT) will these work?

 

[#40Fan]

I would find out what pistons you have installed and use their rings. Different pistons require different rings.

Still with that low of compression after adding the oil, I am willing to bet that you either have piston damage or head/valve damage.

 

[Turbizmo]

I would find out what pistons you have installed and use their rings. Different pistons require different rings.

Still with that low of compression after adding the oil, I am willing to bet that you either have piston damage or head/valve damage.

well thanks for your advice but I already knew it has to either of does i guess i will have to see im taking off my head tomorrow and check and see whats my damage. Im going to take my head no matter what to get it pressure tested and then if it checks out I will go from there. thanks for all your help let u know whats up tomorrow.

like i mention I have JE pistons and Eagle rods thats come in a package How can i order just the JE Piston RINGS? where can I order them?

 

[#40Fan]

Let me google that for you

 

[bullettdsm]

DO NOT ORDER ANYTHING YET!

Wait and see what's going on and what is actually fixable and what is actually broken. Your piston may be bad, your rings may be bad, your valve may be bad, your headgasket may be bad, your bore may be bad etc.

Your decision on what parts you need will be dependant on what is wrong. You can't use those rings if your bore is bad, so you'll want to find out exactly what you need and then make a decision on ordering.

MB

 

[Boosted_talon98]

DO NOT ORDER ANYTHING YET!

Wait and see what's going on and what is actually fixable and what is actually broken. Your piston may be bad, your rings may be bad, your valve may be bad, your headgasket may be bad, your bore may be bad etc.

Your decision on what parts you need will be dependant on what is wrong. You can't use those rings if your bore is bad, so you'll want to find out exactly what you need and then make a decision on ordering.

MB

SOUNDS LIKE someone who has been around the block a few times ....
bizmo.. I took my block in the machine shop and they microscroped my ring and seen gas lubrication .. in cylinder 1.. I am guessing by ## labeled results you went from 1-4 and 1 is also low on you.. sucks mayn def sucks big hairy balls...
Best advice I can give after you take head off check piston wall clearances... or drop it off at a machine shop

 

[saechao04]

I agree with bulletdsm, don't jump to conclusions and start ordering parts! When I had low compression in 1 cylinder it ended up being valve stems. Needless to say I spent a large chunk of money of parts I didn't need.

 

[Turbizmo]

ok thanks guys i will get back at u guys when i take off my head.

 

[Turbizmo]

DO NOT ORDER ANYTHING YET!

Wait and see what's going on and what is actually fixable and what is actually broken. Your piston may be bad, your rings may be bad, your valve may be bad, your headgasket may be bad, your bore may be bad etc.

Your decision on what parts you need will be dependant on what is wrong. You can't use those rings if your bore is bad, so you'll want to find out exactly what you need and then make a decision on ordering.

MB

Ok guys well i took off my head hoping it was a valve or something with the headWTF i was wrong. I took off my pistons and found that piston number 1one it was off i shook it and 2-5 peaces fell of the piston which was the piston rings do to that i took it to a machine shop and told me that the ring did not seal and maybe it broke because of detonation. anyways to get to the point he told me that piston was bad already because the groves where to open and if i was to put new rings they woudld not seal.

so I been looking for a 8:8.1 JE PISTON and i cant find anywhere that only sell 1 piston ### help?

also i was thinking will stock SRT4 pistons work on my block with the eagle rods ? and are there strong to handle 10-15 pounds of boost? assuming i cant find a PISTON

 

[Calan]

Maybe it's just me, but I would be looking for a new set of pistons (all 4), and plan on doing a full engine inspection and possible re-bore. When one piston breaks for no apparent reason, I never trust the others. And if you are that far into the block, you might as well go through the bearings, oil pump, etc. to be sure you won't be back in it again in the near future.

But like i said... maybe it's just me...

 

[bullettdsm]

Ok, here's two problems to overcome. First thing, did the machine shop check the bore to see if they can re-use the current bore without having to go to another bore size (as in just a hone without going over spec)?

If that gets a yes, then you are on a search. You will need to find the correct size/weight of that piston. JE will do all kinds of special lots on the same compression piston. The weights may be different or the wrist pin location or the weight distribution etc. (or even the ring land size. Though I haven't run into that .....yet).

There are numbers on the piston, but that doesn't guarantee that you could even order it from them. It may match up to a number from one of their distributors who you would have to contact and they would have to somehow look it up and they would cry and scream about the effort and not having the info etc. (yeah, unfortunately words of experience).

So I'm not saying you can't find one to match, just that its not as easy as one, two, three.

In addition, if you did want to buy just one piston new, it'll run you about $160 just for the piston (it was just shy of $200 for me to get one recently. That's piston, rings and shipping).

MB

 

[Turbizmo]

Ok, here's two problems to overcome. First thing, did the machine shop check the bore to see if they can re-use the current bore without having to go to another bore size (as in just a hone without going over spec)?

If that gets a yes, then you are on a search. You will need to find the correct size/weight of that piston. JE will do all kinds of special lots on the same compression piston. The weights may be different or the wrist pin location or the weight distribution etc. (or even the ring land size. Though I haven't run into that .....yet).

There are numbers on the piston, but that doesn't guarantee that you could even order it from them. It may match up to a number from one of their distributors who you would have to contact and they would have to somehow look it up and they would cry and scream about the effort and not having the info etc. (yeah, unfortunately words of experience).

So I'm not saying you can't find one to match, just that its not as easy as one, two, three.

In addition, if you did want to buy just one piston new, it'll run you about $160 just for the piston (it was just shy of $200 for me to get one recently. That's piston, rings and shipping).

MB

The guy is going to come to my pad this friday and check out the block since i didnt take off the block just the head and pistons i told him if he could do a side job for me so ill just have to wait and see what he says when he comes. ill keep u posted. thanks

 

[Turbizmo]

The guy is going to come to my pad this friday and check out the block since i didnt take off the block just the head and pistons i told him if he could do a side job for me so ill just have to wait and see what he says when he comes. ill keep u posted. thanks

OK the block is good.

somy question know that mechanic is ### and he is leaving town for a month so i am going to take matters in to my own hands.

my question is has anyone put other pistons rings other than the je piston rings onto the JE 8:8.1 and .020 over ? what rings do u think i should use?

also i just want to know what the Torque spec for the Rod caps are and also what the ring GAP should be? Im more worried about gaping the rings. Putting the pistons on is the easiest .

### help I need to get my car running for a DSM meet and im the only 420a out here

 

[Slo2gen]

OK the block is good.

somy question know that mechanic is ### and he is leaving town for a month so i am going to take matters in to my own hands.

my question is has anyone put other pistons rings other than the je piston rings onto the JE 8:8.1 and .020 over ? what rings do u think i should use?

also i just want to know what the Torque spec for the Rod caps are and also what the ring GAP should be? Im more worried about gaping the rings. Putting the pistons on is the easiest .

### help I need to get my car running for a DSM meet and im the only 420a out here

I would only use JE rings. You can use other rings but you need to make sure they are the right size/width/height. As for the rod caps, if you have eagle rods there are two numbers for them, each is dependent on the rod bolt size. The ring gap is the easiest part, on my first build (its been a while so don't trust these numbers because they may be wrong) I used .016 for the top and .019 for the bottom, I think. Either way you can look that up as well. It seems to me that you just need to give JE a call and read them the number on your piston and call eagle and give them the number off the rod and they should be able to tell you(if you have stock rods you can look up the torque spec in the FSM). I would use some plasti-gauge if you are going to be assembling the motor.

 

[Turbizmo]

yes i have eagle rods.

well i already know what the torque specs are for my eagle rods. Im still tryng to figure out what the Gap On the Piston RINGS are can anyone help me with that? thanks


also does it matter what way the piston is facing it says JE on the inside of the piston but way should it face towards the intake side or the exhaust side?

also what way should the eagle rods Face? is the eagle emblem facing the timing belt or the other way or does it not matter? pls help I want to get up and running this weekend thanks.