Low compression test results - Saxperience

misulko · 8th January 2014, 20:55

Hello guys,

i tested compression in the past and I had the figures:

1. 181
2. 178
3. 181
4. 181

New engine should have around 220ish according what I´ve found here and on web. Recently I had removed my head off. My oil consumption is about 2 litres per 6200 miles.

Should I replace piston rings a will it help to raise compression or should leave alone as it is?

Thanks

wullvfr · 8th January 2014, 21:01

They do seem a bit low but I don't think there is a specific compression rating for the saxo,not that I can find anyway and certainly not in the manual.

So long as the compression is above 10 bar which equates to roughly 160psi so on that note I'd say those figures are ok....

And another thing that seems ok is the fact they are very consistent and within the 2bar limit of each other.

The two litres for every 6k seems quite a bit but tbh it's not absolutely dire as a litre every 3k ain't the end of the world.

I'm starting to wonder if I have a leak so I'll be keeping tabs of my level tomorrow,I'm going to keep a note of the exact level,mileage and date and see how it goes.

misulko · 8th January 2014, 21:12

I know there isn´t a specific number of compression test figures, but one of my friends did full general repair including bottom end honing, changing pistons rings etc and he dialled 220 also here some of guys posted around 220. The thing is I want to do a remap my 743 cams on March, so I want to keep my engine in mint state before it.

wullvfr · 8th January 2014, 21:17

Yeah I fully understand,someone the other day had results of over 220 iirc on here.

Taffymeister · 9th January 2014, 00:33

The above posts are right, they are very similar within the 2bar range. Although if you're wanting the 200+ PSI then you can't go wrong by changing rings (while you're at it, check piston height)

f13sta · 9th January 2014, 15:54

Just check to see if there is any bore scoring.
And then check the float of the pistons. Any side to side movement then your rings are not the best.
To loose that much oil. I'd say you have a leak somewhere.

greyjasper51 · 9th January 2014, 19:06

my 100bhp vtr was 180-190 consistantly so no i wouldnt worry

i think my vts is low on cyl 4 (1 technically as its closest to the gearbox, poxy frogs)

ill check again tomorrow and give you the readings, cammed engines do seem to be slightly lower than std ones

misulko · 9th January 2014, 19:33

Quote:

Originally Posted by f13sta

Just check to see if there is any bore scoring.
And then check the float of the pistons. Any side to side movement then your rings are not the best.
To loose that much oil. I'd say you have a leak somewhere.

I will check that scoring tomorrow. I already checked the float, it´s a bit side to side movement.

greyjasper51: I´ve tested it on std engine.

Ross^p · 10th January 2014, 02:36

Was that compression test wet or dry?

yr51ocw · 10th January 2014, 07:25

things that can dramatically effect the results:

wet or dry
throttle open or closed
engine hot or cold
cranking speed (battery/start motor in good condition)

Did you say you have 743 cams fitted? if so they will reduce the dynamic compression also.

I would hay those figures are of no concern.

misulko · 10th January 2014, 07:41

It was dry test with wide open throttle, cold engine, battery fully charged and bout 5 cranks on each cylinder.

No,that time it was with std cams.

misulko · 10th January 2014, 12:29

f13sta: No bore scoring on any cylinder just a bit dirt on cylinder 2 and 3, just a bit side to side movement on every piston.

jackgibson22 · 26th April 2019, 12:07

2002 saxo VTS...

when im putting my foot down its like a 1.1 theirs nothing their then suddenly about 4.5k vvt kicks in but feels so slow, I've changed the map sensor and the fuel filter and still the same just feels like its hold back on power

any suggestions???

welshpug · 26th April 2019, 13:46

there's no vvt on these.

is the eml on?

MartinObviously · 27th April 2019, 11:31

Quote:

Originally Posted by jackgibson22

2002 saxo VTS...

when im putting my foot down its like a 1.1 theirs nothing their then suddenly about 4.5k vvt kicks in but feels so slow, I've changed the map sensor and the fuel filter and still the same just feels like its hold back on power

any suggestions???

Yes probably a faulty upstream lambda sensor.

It'll be 4k because it's at that rpm the lambda sensor readings are ignored and the fuelling goes into open loop based on TPS position and MAP sensor reading.

Get it read with a code reader and check the live data for the lambda sensor. the 3 plug in a 2002 VTS is fully OBD-II compliant so any generic reader should work.