Lost compression

[jc denton]

Anybody ever had any luck with compression restoring potions?

 

[T9 man]

In the old old days on my old Cortina Mk1 1300 I did have a small benefit from using a substance which at least stopped the smoking from the rings.
If memory serves me correctly it was made by Holt. Not sure how good the modern equivalent would be and what is actually out there for such a job.
I suppose the purist would always remove the pistons and replace the rings.

 

[SLEEPER]

May work on an older british engine but not sure how helpful on a high revving one. Of course it depends on the why its low.

 

[HDi fun]

Holts piston seal was around but I cannot imagine it working on modern engines. Do you know the cause of the low compression?

 

[jc denton]

Its just that I've always thought the MR2 seemed a bit sluggish, it has over 175,000 miles on it. Low compression sprung to mind when I parked it in gear on a slope & leaned on it & the engine turned over.

 

[T9 man]

Forgive me, maybe its just me! But I don't quite understand what your trying to describe as to the symptoms of the possible low compression.

 

[jc denton]

I may be wrong but it makes sense to me that if you can push a car that's parked in gear, there must be low compression right?

 

[T9 man]

I may be wrong but it makes sense to me that if you can push a car that's parked in gear, there must be low compression right?

Your previous post was not the clearest I have ever read. Does the car have difficulty in starting when its warm? What does it idle like? I'd advise that you or someone else check out your starter. I had a friend who was having issues with hard starts when the engine was still warm and especially so after the cold weather set in. He too feared low compression, but it turns out a dying starter was to blame. There are far too many variables with these cars. Run through your ignition system, eliminate some of these variables, and then start considering low compression if you're still not seeing results. Have you actually had the car compression tested? Any garage worth its salt can do this for you and for not a lot of money. Even the AA or RAC can do this for you if you are covered.

 

[jc denton]

Have you actually had the car compression tested?

Yeh! take a spark plug out, stick your finger in the hole & see if the bugger kicks back:blink1:

Maybe I wasn't clear but theres nothing wrong with the starter or the engine, it just feels slightly down on power & I'm assuming its just worn rings/low compression.

When parked in 1st or reverse (handbrake off) its possable to push the car little by little, causing the engine to turn over. Hense I'm assuming low compression.

In fact I don't think anybody has come up with this method yet...which makes me responsable for naming it.:amazed:

 

[jc denton]

GOT IT! I'll call it "the super rocking boundry pushing compression tester technique 2000"

 

[turbonutter69]

You push most cars in 1st or reverse so that won't really tell you much about compression.
When was it last serviced?

 

[SLEEPER]

You cant do a compression test without a gauge . They are about £15 from halfords and extremely accurate if you use them properly.

The MR2 isnt the heaviset car so relatively easy to push in gear.

Oh and spend the money on the gauge not on the can of holts.

 

[jc denton]

Not that bothered really, I'll replace the rings when I get time.

I'd like to research this new technique though. Put your car in 1st or reverse & see if you can push it?! - for one half of a crank rotation.

 

[SLEEPER]

can i do it in the stagea no , can I do it in the civic - easily

the difference a few hundered kg

 

[jc denton]

"the super rocking boundry pushing compression tester technique 2000" indicates that your civic is down on compression Sleeper!

 

[SLEEPER]

Your reply worried me so much I couldnt sleep last night so just in case your new wonder theory was correct I did a compression test on the civic this morning.

(actually the plugs were due be changed and I thought why not )

Happy to report that it is spot on all cylinders which Im afraid means your new theory is ermmmmmmmm................ about as accurate as your ignition timing method. as in not.

 

[jc denton]

Hmm, are you sure your compression tester isn't broken?

 

[SLEEPER]

well it read the same on each cylinder so probably not.

 

[pgarner]

remember being able to move the father in laws rover 400 in gear and my civic.
not even trying the octy at nearly 1600kgs ill end up putting my back out

 

[HDi fun]

remember being able to move the father in laws rover 400 in gear and my civic.
not even trying the octy at nearly 1600kgs ill end up putting my back out

Plus it's diesel so your fighting a 22:1 ish compression ratio as well

 

[pgarner]

this is true