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3
votes
1answer
45 views

Do Compression Rings and Oil Ring Wear at the Same Rate?

Is it possible that the oil control rings might be worn to the point that you're burning significant amounts of oil, but the compression rings still be good? Or do they typically wear out together ...
5
votes
1answer
43 views

Is cylinder leak down test needed if compression test results are fine?

If I compression test my engine and the results are fine, could there ever be any need to leak-down test it as well? IOW, can a leak down test ever fail if the compression test is fine. RELATED: ...
2
votes
1answer
24 views

Converting Cylinder Compression Specs to Inches of Vacuum

If I have the specifications for cylinder compression can I convert that to how much intake vacuum the engine should be pulling? For example, if I have a 4 cylinder engine that is supposed to have ...
2
votes
2answers
33 views

Could this be the result of bad compression?

I've had a bunch of problems with my truck (2000 Ford Ranger) and I've been hoping to sell it. Most recently, I was driving it and the heater control valve snapped. I drove it home and replaced the ...
1
vote
3answers
666 views

Mondeo 04 TDCI bent conrod - worth fixing?

I have a 2004 Mondeo 2.0 TDCI which has issues when starting from cold: lots of white smoke and rough idling until it warms up. Had it tested at several garages, who both diagnosed low compression in ...
0
votes
1answer
331 views

How much Octane Fuel does Honda CBR 250R (India Version) needs? 91 or 93?

Honda CBR250R STD 2013 Model's manual state that fuel(petrol) used should be 91 or more. Seems like they have defined the minimum threshold of RON than stating the optimum RON for the given bike. ...
1
vote
0answers
28 views

Is it wise to use engine compression to help slow down a car to prolong brake life? [duplicate]

I have a 2010 Mercedes C-300 with six speed standard transmission. I'm wondering if it is wise to downshift to get engine compression to help slow down the vehicle when stopping to lessen brake wear? ...
3
votes
1answer
646 views

Low compression and will not ignite after broken camshaft pin and replaced head and gasket

My 95 Geo Metro Lsi 1.0L had a blown head gasket. I replaced the gasket and drove the car for approximately 120 miles before it started spitting and sputtering. Then it died just before I got home. I ...
3
votes
1answer
128 views

Corsa Sport (2007) low compression cylinders 2 & 4

I have been having trouble with my Corsa. It sometimes just cuts out or does not want to start at random times. I have had the car serviced, I have had the starter motor replaced & am now having ...
2
votes
2answers
298 views

What do these compression figures mean

This is a follow up question to What are the causes of fluctuating intake manifold vacuum I have a 2005 Honda CBR600 F4i which suffers from occasional hesitation at low rpm when accelerating. After ...
5
votes
3answers
2k views

Cylinder 1 and 4 has low compresion, after engine has been redone

I have a Opel Corsa 1999 B type. We had a mechanic redo the engine about 4 months ago, but this week it just does not want to start. Today had other mechanic look at the engine, and did a quick ...
0
votes
3answers
347 views

Typical Stock Boost Values

For an engine that is boosted out of the factory, what are typical maximum and average boost values? Are they conservative in the 5-6 PSI range or do they get more aggressive getting up to 10-15 PSI? ...
1
vote
1answer
50 views

Strokes during compression test?

Just wondering what the general consensus out there for the amount of times the vehicle turns over during a compression test? I have heard anywhere from 5-8, and personally crank 7. What is the ...
1
vote
1answer
1k views

Does a warped engine block affect compression test?

Check other questions, and did not see an answer. Backstory: Driving around, discovered pin hole in radiator. Chose to drive home, since I was at my exit, and I lived right there. Blew head gasket. ...
2
votes
2answers
865 views

Motorcycle 125cc question about PISTON condition and battery

Last year I bought a 125cc bike Modenas brand, most likely unknown to you. It is a moped. http://www.modenas.com.my/v2motorcycle.asp?id=70 It can go as fast as 110 km/h enough for the city and not ...
16
votes
3answers
5k views

Static vs. Effective compression: Why does higher effective compression not require higher octane gas?

Background I've been trying to do a lot of research on boost lately because I'm planning on running a moderate turbo setup on my daily/light-duty-autox car in the future. I'm trying to get into the ...