Too much oil pressure? Compression ok?

[Texas gst]

Ok I've looked around and can't seem to find an actual number for oil pressure. Story is my factory sending unit went bad, got an autometer 100psi Guage cheaper than the sender so put it in. Oil pressure will max out the gauge when giving it gas. Should I be worried? If so, what might be wrong? If not, cool I'm ok. And checked compression it is between 120-125 all the way across. Is that ok?

 

[unisonicz]

If you have deleted your Balance Shaft it will easily max out a 100psi gauge.

 

[habitatguy187]

Compression numbers are not good. You're probably leaking compression into the crankcase causing high oil pressure, which isn't good for the car.

 

[unisonicz]

Oh.... I didn't even see the compression numbers. Sorry about that.

 

[Texas gst]

You talking a rebuild? Just the head? It runs good. No issues or trouble with it. I don't run it hard or anything either

How much compression should I have. I was thinking 125 was ok?

 

[BIRDCLAWTSi]

Do you always max out the gauge? How is it at hot idle? It should be 10 psi. Hot idle to 120psi. without balance shafts. That is a pretty general number. Cold starts will give you high numbers, Especially in the winter time with thick oil.

 

[Texas gst]

Cold idle first start 75. Warm idle 25. Hot idle not sure, haven't driven it except 1/2 mile today after putting in the gauge. Is my compression too low? I guess I should drive it a bit first. I put a high mileage 5-30 recently. Probably going to castrol syntec 5-30 or 10-30 in a week or so.

On a side note, if it matters, after doing the oil change I have started to notice some bluish smoke when accelerating (oil burn?) The oil I drained (just got this car) was BLACK and could smell a touch of gas. And does anyone know how much compression I should have?

 

[habitatguy187]

Compression numbers should be closer to 160 across the board, not sure what the service limit on a 2g is, but I know on a 1g it's 122psi. You need to do another compression test, make sure the car is warmed up first.

Do what is called a "dry" test first, then do a "wet" test in that same cylinder. All that means is that you test it normally, then take a oil cap's worth of oil and put it in the cylinder and do the test again. If the numbers increase dramatically then your rings are bad, if not then it's leaking out elsewhere. (head gasket or head)

 

[Texas gst]

great!!! thank you. My test earlier was "cold" when checking. I will try that tomorrow at work. Thanks again.

 

[bradselph]

i know for me when i crank my car up in the morning it idles at about 60-70 psi and gos down to 40 after a few minutes then i drive off and by the time i get to work it wil idle around 11 psi and on a hard pull with this stock 4g64 it seems to hit 100 psi around 4.5k to 5k rpm and stops climbing till i hit rev limit at 6k

 

[Texas gst]

Ok, so here's what I got. Looking at the engine going left to right. Dry-142,138,135,132. Wet-155,147,145,143. Now "supposedly" this engine was rebuilt about 10k miles ago and bored 30 over, angle ground, port and polished. Any thoughts on any of this?

 

[9!'clipseDOHC]

1995-1999 Eclipse and Talon

2.0L 4G63 Turbo engine
Compression ratio 8.5:1
Standard compression 178 psi
Service limit 133 psi

You are right on the line there. If you car engine was rebuilt, it wasn't done well or it wasn't broken in correctly. Is it supposedly still on the stock pistons?

As far as the oil pressure, Do you have balance shafts? On my engine, 6 bolt with no balance shafts, I see about 80-90 psi on cold starts and it easily maxes out the 100 psi gauge when driving. Once it is warm and at 750 idle I'm at about 20 psi.

100 psi oil pressure gauges on DSMs, especially without balance shafts, are a joke. I only have it because it was free.

 

[Texas gst]

So how do I fix it? Complete rebuild? Don't know on the pistons. I'll check with another gauge too just in case. But if it's right are we talking full rebuild? I am somewhat knowledge on mechanic work and can do most if not all myself, but brand new to dsm's. You talking new pistons & valve job, full rebuild, just new pistons? I know it's kinda hard to say b/c if I pull it apart and has stock pistons but has been bored over, than maybe just the "right" pistons. And the big question---is it worth it? How much are we talking if I do the work (minus machine shop work)?And thank you sooo much for the actual compression specs.

 

[jrohner]

Ok, so here's what I got. Looking at the engine going left to right. Dry-142,138,135,132. Wet-155,147,145,143. Now "supposedly" this engine was rebuilt about 10k miles ago and bored 30 over, angle ground, port and polished. Any thoughts on any of this?

Find out what pistons (compression ratio) were used.

 

[9!'clipseDOHC]

So how do I fix it? Complete rebuild? Don't know on the pistons. I'll check with another gauge too just in case. But if it's right are we talking full rebuild? I am somewhat knowledge on mechanic work and can do most if not all myself, but brand new to dsm's. You talking new pistons & valve job, full rebuild, just new pistons? I know it's kinda hard to say b/c if I pull it apart and has stock pistons but has been bored over, than maybe just the "right" pistons. And the big question---is it worth it? How much are we talking if I do the work (minus machine shop work)?And thank you sooo much for the actual compression specs.

I wouldn't really worry about your oil pressure, it sounds pretty normal to me.

As far as your engine. It is hard to say. If the the cylinders were bored correctly and the right pistons and rings were used but it was just broken in wrong, then you could probably just get away with a new set of rings. However if the it was a crap machine job or reused pistons in a bored out cylinder, then you are going to have to start from scratch, new pistons and machine work. Either way the engine will need to be pulled.

Is it worth it? That depends on what is actually wrong with it and what your goals are. If you just want a cheap, reliable commuter car, then no it's probably not. Sell it or drive it 'til it dies. If you are set on this car and you have high performance aspirations (and plenty of money), then this is a great opportunity to build the block it the way you want it. Forged pistons and rods, MLS headgasket, ARP hardware, etc. Or if you have the time (is this your DD?) to be without the car and you just want it to be "fixed" you can pull the motor and take it to a machine shop and have them do a "stock" rebuild. It's up to you.

Also since your compression numbers are still pretty low even with the wet test, your valve seals could be bad. That would be a lot cheaper and easier to fix then the pistons rings. You could replace the valve stem seals and then try the compression test again and go from there. To replace the valve stem seals you would have to remove the timing belt so it's still a pain in the butt but not nearly as involved as pulling the whole motor. You will need a special tool to be able to remove the valve springs with the head still attached though. Other then that it's an easy job.

Hope this helps!

 

[Texas gst]

The guy I got it from got it in a trade so the only way to know is if I pull it all apart. This is my daily driver so if/when I pull it all will only be when I'm ready and able to really do some work on it (rebuild). Unless anyone knows any "easy" way to identify pistons. I looked down the plug holes and can't really see any stampings, atleast not enough to make an identification. Can see some numbers or letters but can't make anything out on them

 

[habitatguy187]

Remember that a stock rebuild is more than enough for most people's power goals.

 

[Texas gst]

350 would be nice but 300hp is ok if I got there. Any general suggestions. Maybe I should just tear it apart, put new pistons if needed and call it a day? Or is that just a stupid thought? Dont really think I need a full rebuild, but that's why I'm asking. Better question, if it was yours, what would you do? Let's put a goal of 350hp down the road so I don't have to redo anything. Pretty sure it's all stock except for--bov, air intake, intercooler, boost and oil psi gauge, short shift, I think that's it. And if it matters it's the "jdm" engine with the red valve covers.

 

[habitatguy187]

350whp is absolutely no problem for a stock rebuild. If it were me personally, I would try to save up some money and buy a cheap DD, or possibly save up some money, borrow a car from someone, and then rebuild the engine.

Either way, you can probably drive it like it is now, but I'd try to let it warm up before taking it out on the road. My current car had either bent valves or bad valve seals, and it leaked compression into the crankcase, raising my oil pressure pretty high (don't have a real oil pressure gauge). Anyway the high oil pressure kept causing oil leaks here and there, so I decided to pull the head and put my old one on from the parts car. High oil pressure is never a good thing, one reason why I'll never delete my balance shafts.

 

[Texas gst]

Thanks for all the help. I'll start saving up. Anyone need their yard mowed. .