[devildriver]

Hello fellow auto aficionados!
I come to you all in a time of my friend's dire need for advise.

A very good friend of mine who is not a member on team.bhp but is a regular visitor is facing some issues with his Ford Fiesta 1.6 petrol, 2009 model, bought pre-owned in 2012, driven 65K kms, always been serviced in time till date only from Ford authorised workshops pre and post purchase.

He was driving after rain in Gurgaon and his car aquaplaned at around 80-90 kmph, skid on the road for around 100-200 m then went off the road, hit the left side kerb, climbed it and came to a halt on it. This happened at around 3 am. The car shut down and he got out to inspect the damage. The damage was a busted front bumper, fog lamp and the plastic below the bumper which ford calls engine guard which is more of a skirt and a busted oil chamber. Since he couldn't find a tow truck at the odd hour, he babied the car back to his place around 800 m from the accident site at low rpms. Parked it and left the country for an office project trip of three months.

He came back last week, saw that the car's battery had died and enquired with Delhi ford and Harrpreet Ford for oil pan and ended up taking the car to Harpreet Ford, Gurgaon. The service adviser started off by saying that he should not have driven the car after oil chamber damage and also said that my friend might be facing considerable engine damage. He knew it was possible and that he'd made a massive mistake by driving it home but he claims that the car was running fine when he got home and didnt have the oil pressure or engine malfunction lamps on.

Today, he went back to the service station to get an update on his car. They had flushed the engine with 2 litres of new engine oil (at my pal's request), replaced the oil chamber, oil filter, let the sealant/ glue cool down, refilled oil and called him before they started the engine, again as per his request. My friend called me and I went right away as I work in the vicinity of the workshop and was very curious of the work being done on his car.

The car started just fine. The service guy let it run at idle for 5 min without revving it. Opened the bonnet to check for odd noises from the engine, declared that there was no odd noise. Then the service head who was around recommends an engine compression test to determine if the engine is actually fine.

Steps performed by the mechanic running engine compression test:
1) Disconnected air intake
2) Took off the airfilter and plastic engine cover
3) Took off the spark plug actuators/ boots (pardon my layman parlance)
4) Unscrewed the sparks plugs
5) Got a pressure gauge connected to cylinder 1
6) Cranked the engine and let the crankshaft crank for around 1-15 seconds.
Step 6 was repeated on all 4 cylinders but the time for which he cranked the cylinders varied widely from 10 to 15 seconds. After taking down the readings of all cylinders, he goes on to perform a wet test after putting in a little bit of oil into all cylinders, one at a time.

The readings:
- There was a wee little bit of oil on 3 of the spark plugs.

- Dry test:
Cylinder 1: 6 kgm/ bar
Cylinder 2: 4 kgm/ bar
Cylinder 3: 6 kgm/ bar
Cylinder 4: 6 kgm/ bar

- Wet Test:
Cylinder 1: 8 kgm
Cylinder 1: 6 kgm/ bar
Cylinder 2: 8 kgm/ bar
Cylinder 3: 8 kgm/ bar
Cylinder 4: 8 kgm/ bar (the reading looked slightly higher on the gauge on cylinder 3)

Please note that I didn't pay heed to the units of scale on the pressure gauge used to run the test. My bad. Assuming that it was in either in bar or kgm.

Observations and suggestion from service head and a senior mechanic:
- Ideal compression pressure readings should range from 12-14 bar/kgm
- Low compression readings from engine are due to the car being driven after accident, irrespective of the fact that it was driven for <800m at slow speeds in low rpms
- Suggested that we go for a engine check which would require opening it up. They would then give an estimate of engine service/ overhaul. I am not sure if he would open the top half cylinder containing part or if they would disassemble it from the car and take it entirely down. Said it would range INR 50-60K

Then I insisted that they start it up again and let the engine run at idle. This was done in attempt to recharge the drained battery as well. Opened the bonnet again for noise and there wasnt any unfamiliar sound. This went on for almost 20 min. No issues, the temp gauge reading in the instrument cluster came to normal operating temp. Then we decided to take the car for a short drive with the workshop's test driver. Went for about 3 km to and fro and came back. I drove the car and it felt smooth with out any misfire or gaps or jerks in throttle response. The car did feel a tad slower than my car like by 5-10%. It always did feel a tad slower in comparison to my car even earlier to the accident but now it felt a but slower than it did earlier.

We drove back to the workshop and I stalled the car while entering it. The battery didn't crank the engine and died. Had to jump it.

Now, we popped the bonnet, the car was quite hot, hotter than usual for sure. Slightly weird noise from the engine. Could one of the belts as the car was not started/driven for more than 3 months.

The test driver says that the engine is just fine and he didn't observe any lag or loss in power and we shouldn't be investing in it till there is actually a problem. Even the service head is of the same opinion, says the engine is good to go or fine for now. The only implications he says will be slight increase in engine oil consumption and shorter engine life.

I welcome your suggestions and knowledge on the following concerns:

1) Was the test performed accurately? Because, I googled it and read from a couple of sourced that:
a) the engine should be warmed to optimum temperature but the mechanic just ran it for less than 5 min and the cylinder head was not even warm when he ran the test
b) the engine is to be given full throttle while performing the test for best results. Is this true and mandatory while performing the test? The mechanic didnt give it any throttle. Just cranked it with the started motor. Would the car given out accurate and higher pressure readings is given full throttle?
c) The fuel injectors are to be disconnected before performing the test. Is this true or mandatory? No such thing was done by our mechanic

2) Should we take the car for now as it is, run it for a month and then replace oil with fully synthetic and run the compression test again in the right manner at a better workshop/ mechanic?

3) Should my friend just keep the car as it is and run it till it lasts? He really loves this particular car and prefers it two an Amaze petrol and a Verna crdi in the family. But he is also open to buy another car, mostly a new hatch back (logical but last option) or another used sedan (most preferred option) if the Fiesta would require considerable repair (50K and above) ahead in the next 30-40K Kms/ 12-18 months on the engine front. He isnt really excited of the other Fiesta level handling 100+ bhp cars in the used car market with relatively low cost parts and service

Please advise!!

[abhishek46]

Hello there,
First of all, your friend should not have even touched the ignition key after the Oil sump cracked. But, what has happened can't be undone. So, lets leave that aside.

Absence of Oil can lead to complete Engine Seizure. But partial loss of compression is a rare side effect in case of Oil leakage.
Please get the compression test repeated, and proceed to open the engine and inspect the internals, if same results crop up. In general 10% variance of compression against manufacturer values is considered okay.

It is not needed to test the compression using full throttle. But, engine needs to be at normal operating temperature (5-10 min idling can achieve this).

[Jaggu]

Originally Posted by devildriver

1) Was the test performed accurately? Because, I googled it and read from a couple of sourced that:
a) the engine should be warmed to optimum temperature but the mechanic just ran it for less than 5 min and the cylinder head was not even warm when he ran the test
b) the engine is to be given full throttle while performing the test for best results. Is this true and mandatory while performing the test? The mechanic didnt give it any throttle. Just cranked it with the started motor. Would the car given out accurate and higher pressure readings is given full throttle?
c) The fuel injectors are to be disconnected before performing the test. Is this true or mandatory? No such thing was done by our mechanic

2) Should we take the car for now as it is, run it for a month and then replace oil with fully synthetic and run the compression test again in the right manner at a better workshop/ mechanic?

3) Should my friend just keep the car as it is and run it till it lasts? He really loves this particular car and prefers it two an Amaze petrol and a Verna crdi in the family. But he is also open to buy another car, mostly a new hatch back (logical but last option) or another used sedan (most preferred option) if the Fiesta would require considerable repair (50K and above) ahead in the next 30-40K Kms/ 12-18 months on the engine front. He isnt really excited of the other Fiesta level handling 100+ bhp cars in the used car market with relatively low cost parts and service

Please advise!!

1- Yes almost as recommended.

a) this should be fine.
b) Ideally yes, this is to fully open the air intake side to let max air in.
c) yes there would be a slight dip in compression, since the fuel from injectors tend to wash the oil away. But then wet test should have it covered to an extent.

2- Yes please do, keep an eye on engine temperature, oil consumption and coolant levels and use it for couple of 100 kms. If things are fine, just continue as it is.

3- If things are fine, no harm in continuing with the car.

At the end of the day if the car is running fine, don't bother too much. Damage would have been minimum. Do a full oil and filter change for now, run for 500-1000 kms while keeping a check on oil and fuel consumption. If things are fine, keep driving till your friend wants to keep it

[SS-Traveller]

First question: Why not go to a reliable FNG who won't try to rip you off? There are plenty of reliable FNGs in Delhi and Gurgaon that many BHPians vouch for, and you can use the directory section to find them.

Originally Posted by devildriver

- There was a wee little bit of oil on 3 of the spark plugs.

Plugs should be dry / sooty - need to re-confirm plug condition after 500 km.

- Dry test:
Cylinder 1: 6 kgm/ bar
Cylinder 2: 4 kgm/ bar
Cylinder 3: 6 kgm/ bar
Cylinder 4: 6 kgm/ bar

- Wet Test:
Cylinder 1: 8 kgm ???
Cylinder 1: 6 kgm/ bar ???
Cylinder 2: 8 kgm/ bar ???
Cylinder 3: 8 kgm/ bar
Cylinder 4: 8 kgm/ bar

Which one is correct in the wet test? Even pressure on 3 cylinders and 25% lower on #2 as per the dry test. As long as the cylinder is firing properly, and the plug isn't fouling up every 500-1000 km, doesn't matter what the reading is.

Observations and suggestion from service head and a senior mechanic:
- Ideal compression pressure readings should range from 12-14 bar/kgm

At almost 50% drop in compression, your engine is not expected to deliver adequate power - which is not the case here. Petrols generally aim for 8-11 bar of pressure, depending on the compression ratio. Not sure what the compression ratio of this engine is, but I'd guess not more than 10:1.

- Low compression readings from engine are due to the car being driven after accident, irrespective of the fact that it was driven for <800m at slow speeds in low rpms

An engine with worn out components, because it has been driven without oil, will sound quite noisy - it's not the pistons-rings-cylinder bore that wear out, but also bearings, oil pump, and a whole lot of other things. You don't seem to report an unusually noisy engine.

- Suggested that we go for a engine check which would require opening it up. They would then give an estimate of engine service/ overhaul.

Thank God this guy isn't a cardiac surgeon, but merely a mechanic. I am imagining him doing an open heart surgery to check if someone's hart is fine!

Now, we popped the bonnet, the car was quite hot, hotter than usual for sure. Slightly weird noise from the engine. Could one of the belts as the car was not started/driven for more than 3 months.

Check components like fan belt, water pump and leaking/jammed radiator.

...the service head is of the same opinion, says the engine is good to go or fine for now. The only implications he says will be slight increase in engine oil consumption and shorter engine life.

And they themselves suggested the engine needs to be opened up to check... How nice of them to revise their opinion once your friend refused to spend money like a billionaire.

1) Was the test performed accurately? Because, I googled it and read from a couple of sourced that:
a) the engine should be warmed to optimum temperature but the mechanic just ran it for less than 5 min and the cylinder head was not even warm when he ran the test
b) the engine is to be given full throttle while performing the test for best results. Is this true and mandatory while performing the test? The mechanic didnt give it any throttle. Just cranked it with the started motor. Would the car given out accurate and higher pressure readings is given full throttle?
c) The fuel injectors are to be disconnected before performing the test. Is this true or mandatory? No such thing was done by our mechanic

Was all this compression testing done on a running engine?

2) Should we take the car for now as it is, run it for a month and then replace oil with fully synthetic and run the compression test again in the right manner at a better workshop/ mechanic?

And in what manner would fully synthetic oil improve the engine? Please continue to use the grade and specification of recommended for the engine, or perhaps a slightly thicker grade.

But he is also open to buy another car, mostly a new hatch back (logical but last option) or another used sedan (most preferred option) if the Fiesta would require considerable repair (50K and above) ahead in the next 30-40K Kms/ 12-18 months on the engine front.

Ah... the thought of buying a new (or pre-owned) car always excites any petrolhead!

[Sutripta]

If your fears are because of oil starvation, open the cam cover and check the lobes for scuffing. Other verification of lubrication failure will require a teardown.
Compression (ie piston rings/ cylinder bore) will not be high on the list of what is likely to be damaged. Well after cams, bearings, turbo bearings, timing chains (if used).

Cylinder with lower compression:- plug looks same as others?

Regards
Sutripta

[Jeroen]

The compression readings are all on the low side. But unlikely to have been caused by oil starvation. If the car runs fine otherwise as suggested don't bother too much. You might want to try an engine cleaner additive or so. You might have some sticky piston rings. Although the readings seem to be very consistent. To the point you might want to re do the compression test with a different set of measuring equipment all together.

Jeroen

[ads295]

Hello guys.

Came across this thread. I had a question for my car as well.

I have a 2005 Hyundai Sonata 2.7L V6 that I'm bringing back to spec. Just for posterity I did an engine compression check on my car today. The car's engine is very smooth, no noises except for the belt and rollers which are going to be changed shortly, spark plugs are clean, no engine oil leaks anywhere. This was done just because I felt like doing it.

Now, the Hyundai service manual states that the pressure should be 170psi nominally and at least 150psi on the lower side. The difference between two cylinders should not exceed 14psi.

I did the check today on all six cylinders (dry only) and the readings were all 75-ish psi! Consistent 75psi across all cylinders, give or take 5psi at max.
I'm a little shocked but also puzzled. If something is off, how can it be so uniformly off across all cylinders? If there's something really wrong then perhaps it should be more random?

I'm repeating the test with some oil tomorrow. Let's see how that goes. From what I've read, if the wet test results don't change much then the head or valves might have to be looked at.

My mechanic is an old school guy who trusts his gut instinct more than such readings. He's certain the engine is OK since it's noise free, runs well, and the exhaust is always wet/dripping.

Any inputs are welcome.