I need some advice on compression
Discussion
Hi guys:
I just go get the compression test done on my car, it doesn't read good. It is 130, 150, 120, 150 psi. The shop technician says the motor was been sitting for too long and 2 of the cylinders rings lost its elasticity because of it, and he suggust me to drive it a bit more and see if it will free up a little bit.
Is that possible for rings to get in situation like that?? Will it come back to life? Or I need to change the rings? The car was once been stored for more then 3 years, and was never fired up during the period, then the next owner bought it and work on the car, but he only drove it for 2000Km in the past 3 years.
I just go get the compression test done on my car, it doesn't read good. It is 130, 150, 120, 150 psi. The shop technician says the motor was been sitting for too long and 2 of the cylinders rings lost its elasticity because of it, and he suggust me to drive it a bit more and see if it will free up a little bit.
Is that possible for rings to get in situation like that?? Will it come back to life? Or I need to change the rings? The car was once been stored for more then 3 years, and was never fired up during the period, then the next owner bought it and work on the car, but he only drove it for 2000Km in the past 3 years.
You can drive it and see if it improves. Generally compressions shouldn't range more than 15 psi.
I bought an old car that had been off the road 15 years. It smoked a bit at first but came right. On the other hand I got a used motor for our Landrover which had been sitting around for a while. It didn't improve so I recently did the rings and bearings. The rings were so soft I could straighten them out completely without them breaking.
The odds are however, you will have to do the rings.
I bought an old car that had been off the road 15 years. It smoked a bit at first but came right. On the other hand I got a used motor for our Landrover which had been sitting around for a while. It didn't improve so I recently did the rings and bearings. The rings were so soft I could straighten them out completely without them breaking.
The odds are however, you will have to do the rings.
Hi,
What is the model/year of the Esprit? You might be experiencing the onset of piston crowning. You could do a 'wet' compression test to verify that it is indeed the rings. Repeat the test, but squirt a shot of oil in the cylinder before doing the test. If the values improve, it's definitely the rings, if not, it may be a valve issue.
Lotus specifically advises against using any kind of engine flush as the great amount of oil system plumbing makes it very hard to ever get all the flush out. It's much better to do a couple oil changes, say at 500 mi. intervals to get any gunk out. Hope this helps...Happy Motoring! Jim'85TE
What is the model/year of the Esprit? You might be experiencing the onset of piston crowning. You could do a 'wet' compression test to verify that it is indeed the rings. Repeat the test, but squirt a shot of oil in the cylinder before doing the test. If the values improve, it's definitely the rings, if not, it may be a valve issue.
Lotus specifically advises against using any kind of engine flush as the great amount of oil system plumbing makes it very hard to ever get all the flush out. It's much better to do a couple oil changes, say at 500 mi. intervals to get any gunk out. Hope this helps...Happy Motoring! Jim'85TE
Yeah~ I did the leak down test and the two low compression cylinder snap back up to 150 right away. :T
I normally do oil changes every 3 months for my cars, and I never really try any oil addictives at all. However, I was thinking about giving those oils that claimed to be able to restore compression a try. Because either way, I will be end up doing the rings. I am just afraid that these so called restorer will leave some permanent and harmful effect to the motor......
I normally do oil changes every 3 months for my cars, and I never really try any oil addictives at all. However, I was thinking about giving those oils that claimed to be able to restore compression a try. Because either way, I will be end up doing the rings. I am just afraid that these so called restorer will leave some permanent and harmful effect to the motor......
zak_62,
There is a difference between a 'wet' compression test and a leak-down test. In a leak down test, a special tool is used and the block is then pressurized using compressed air. You watch the pressure gauge and how/when it drops to dtermine a variety of engine ills. Happy Motoring! Jim'85TE
There is a difference between a 'wet' compression test and a leak-down test. In a leak down test, a special tool is used and the block is then pressurized using compressed air. You watch the pressure gauge and how/when it drops to dtermine a variety of engine ills. Happy Motoring! Jim'85TE
zak_62 said:
Oh I see~ So what I did about adding some motoroil into the cylinder is actually call a Wet Test then~
Zak,
In a word...Yep! Sorry to hear that the values increase when a wet compression test is performed, this definitely points to the rings. As you have an '87 w/ nikosil alloy liners and forged pistons, you can rule out piston crowning.
The only fix is to replace the rings. Make sure to check the liners for any sign of piston sapping damage to the Nikosil.
If the car has mid to high mileage, you may want to consider rebuilding the lower half of the engine (new Main and ConRod bearings) and doing a 3-angle grind on the valves as well as replacing the guides as long as the head is off and the bottom is open. It will be well worth the effort. Happy Motoring! Jim'85TE
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