Technical Compression test help

[The Panda Nut]

Simple problem. I want to do a compression test on our 169. Its a 2011 1.2 VVTI. What do I need to remove without risking damage before doing the test. ECU plugs or injector wiring and coil loom. We have some blue smoke which needs sorting and I want to find out what the likely culprit is.

Second issue is I seem to be able to get a decent 312 1.2 engine which shoud be the same as ours for not much money, so does anyone know if there would be issues just swapping the whole lump. A low miler would answer all my issues and it would allow a complete inspection clean and opportunity to fit new clutch and ancillaries before fitting giving future proofing. I would have a still decent 1.2 lump to sell off cheap to recoup some cost at the same time. MAy be be getting ahead of myself with this but it could be the path of least aggro.

 

[koalar]

Simple problem. I want to do a compression test on our 169. Its a 2011 1.2 VVTI. What do I need to remove without risking damage before doing the test. ECU plugs or injector wiring and coil loom. We have some blue smoke which needs sorting and I want to find out what the likely culprit is.

Second issue is I seem to be able to get a decent 312 1.2 engine which shoud be the same as ours for not much money, so does anyone know if there would be issues just swapping the whole lump. A low miler would answer all my issues and it would allow a complete inspection clean and opportunity to fit new clutch and ancillaries before fitting giving future proofing. I would have a still decent 1.2 lump to sell off cheap to recoup some cost at the same time. MAy be be getting ahead of myself with this but it could be the path of least aggro.

I took all the spark plugs out and removed the plug off the ecu (battery temporarily disconnected)

can't remember exactly but over 200psi on a Good cylinder

I have a feeling it was 220psi but have chucked my notes away. Timing needs to be spot on otherwise it will be slightly lower

 

[portland_bill]

As Koalar says, disconnect the ECU, then it will not try to generate a spark, or inject fuel.
Throttle needs to be wide open. Your car is 'fly-by-wire', so no actual throttle cable. With the ECU disconnected, the throttle butterfly in the intake probably won't operate, so you'll need to open it manually. Move it gently, and prop it open with something that will not fall in, but won't restrict the airflow. A lump of wood might work, as long as it does not shed splinters.
Spin the engine over several revs, until the gauge stabilises. Put a teaspoon of oil into the cylinder, and retest. A significant increase in pressure suggests piston rings. No change from a low reading, suggests valves or head gasket. These engines are not prone to valve or ring problems, unless overheated. Head gaskets do fail (although they are much better than earlier engines), but are not that difficult to replace. Just ensure the new gasket is not removed from its protective packaging until ready for immediate fitment, and that you fit it the right way up, as otherwise it blocks the oilfeed to the cam. New gaskets are coated with a sealant that cures when exposed to air. It should be supplied sealed, if not, reject it. Once opened, it needs to be fitted, and the head put on without delay, or you lose the benefit of the sealant, and will probably be doing it again soon.

If the head gasket or the rings have failed, the most likely cause is overheating. Replacing gasket or engine without fixing the cause of the overheating will result in another similar failure shortly afterwards. A full replacement engine can be easier, especially as they are cheap. (Little demand) Be sure the replacement is in good condition, and replace the timing belt, tensioner and water pump to prevent pain later.

 

[koalar]

As Koalar says, disconnect the ECU, then it will not try to generate a spark, or inject fuel.
Throttle needs to be wide open. Your car is 'fly-by-wire', so no actual throttle cable. With the ECU disconnected, the throttle butterfly in the intake probably won't operate, so you'll need to open it manually. Move it gently, and prop it open with something that will not fall in, but won't restrict the airflow. A lump of wood might work, as long as it does not shed splinters.
Spin the engine over several revs, until the gauge stabilises. Put a teaspoon of oil into the cylinder, and retest. A significant increase in pressure suggests piston rings. No change from a low reading, suggests valves or head gasket. These engines are not prone to valve or ring problems, unless overheated. Head gaskets do fail (although they are much better than earlier engines), but are not that difficult to replace. Just ensure the new gasket is not removed from its protective packaging until ready for immediate fitment, and that you fit it the right way up, as otherwise it blocks the oilfeed to the cam. New gaskets are coated with a sealant that cures when exposed to air. It should be supplied sealed, if not, reject it. Once opened, it needs to be fitted, and the head put on without delay, or you lose the benefit of the sealant, and will probably be doing it again soon.

If the head gasket or the rings have failed, the most likely cause is overheating. Replacing gasket or engine without fixing the cause of the overheating will result in another similar failure shortly afterwards. A full replacement engine can be easier, especially as they are cheap. (Little demand) Be sure the replacement is in good condition, and replace the timing belt, tensioner and water pump to prevent pain later.

everything written here is correct

I didn't bother with the WOT and still got valid results.

2011 1.2 eco with flyby wire throttle

 

[The Panda Nut]

Thanks everyone. When she brings the car back I shall grt testing. I hope its all healthy.

Whats the prevailing feelings on a 312 engine in the 169. As this is already the fly by wire VVTI I am assuming the basic lump would be a striaght swap. Its one for the future as the miles are piling on this car it will probably pass 100K this year so this may be a more possible proposition. I dont ant to swap ecu's so presume that if the injectors are all the same even those would not need swapping.

 

[koalar]

simple answer is I don’t know. I have never tried or know of anybody that has

I suspect any 1.2 69hp will work or could be made to work which opens up the 500 and punto range as a possible donor. As long as the sensors an manifolds are in the same positions I can’t see any obvious reason why not. Normally it’s just a matter of unbolting and replacing any ancillaries that don’t match.


100K is still only a baby. I have had a 1.1 go passed the 200K mark

 

[The Panda Nut]

simple answer is I don’t know. I have never tried or know of anybody that has

I suspect any 1.2 69hp will work or could be made to work which opens up the 500 and punto range as a possible donor. As long as the sensors an manifolds are in the same positions I can’t see any obvious reason why not. Normally it’s just a matter of unbolting and replacing any ancillaries that don’t match.


100K is still only a baby. I have had a 1.1 go passed the 200K mark

Thanks I don't know either but agree with your thoughts. I am probably just needing to do the valve stem seals. We are getting a puff of smoke after startup. Its enough to have me concerned but its running fine. I would only consider if the engine was nearly new and low miles or its just not worth it. It will probably outlast me be a number of years!

 

[timmycm850]

With a puffin smije after start up. Uf its balanced numbers once you've done the compression test then just do timing belt head gasket snd new valve guide oil seals to your own engine. No issues with compatability then.

 

[DaveMcT]

For major engine work AND if you don't have air-con, it's well worth removing the front bumper and radiator frame for better access. The bumper bolts tend to corrode so its a great excuse to get them all sorted and coated with anti seize.

If you do have air-con, it's not worth the cost and hassle of taking it all off. But, I'd still suggest you do those pesky bumper bolts.

 

[The Panda Nut]

Well just did the compression test 1,3 &4 all 135+psi. 2 was 148. A little oil in 1 and the compression rose to 148. All within tolerance and pressure was maintained in all so I dont think any issues except no 1 plug which had been cross threaded by someone before we go the car was a total pig to get back so the heads coming off when the cam belt is next done so that can be corrected, or we shall look out for a low mile 12 plate 169 or a nice low mile lounge 312 and px it within the next few months. Trouble is we all rather prefer the 169 which is such a cheeky car and so much smaller than the newer one. At least this will give me a price point to make a decision. As we have some rust on the front rail by the engine moiunt pxing may be the sensible bet.

Does anyone know what the 169 69HP compression should be?

 

[koalar]

Well just did the compression test 1,3 &4 all 135+psi. 2 was 148. A little oil in 1 and the compression rose to 148. All within tolerance and pressure was maintained in all so I dont think any issues except no 1 plug which had been cross threaded by someone before we go the car was a total pig to get back so the heads coming off when the cam belt is next done so that can be corrected, or we shall look out for a low mile 12 plate 169 or a nice low mile lounge 312 and px it within the next few months. Trouble is we all rather prefer the 169 which is such a cheeky car and so much smaller than the newer one. At least this will give me a price point to make a decision. As we have some rust on the front rail by the engine moiunt pxing may be the sensible bet.

Does anyone know what the 169 69HP compression should be?

Mine is over 200 psi. 2011 1.2 69hp.

With elcheapo gauge

God knows how accurate the gauge is.

Looking at the punto section they are usually around 175 psi to over 200 psi

 

[varesecrazy]

Cranking speeds maybe..

 

[koalar]

Cranking speeds maybe..

Possibly makes a difference

Timing definitely does and it’s even across the cylinders

I would expect a bit of variation in cheap gauges but 1/3 seems a lot to me.

But my gauge could be 1/6 high and the other 1/6 low

You can get a good idea when you turn the crank pulley over by hand with the spark plugs in. it’s hard to explain there’s almost a solid resistance as each piston reaches top dead centre and holds there. And as you push further it instantly releases. Where as if the timing is out it’s a more gradual raise and release of pressure. But you really need to have felt a good car first

 

[koalar]

Does this cat have an oil catch can due to a regular build up of sludge ?

You say you have a bit of smoke on start up


White
Black
Grey
Blue

 

[DaveMcT]

Repeat the tests with all spark plugs removed (and coils trigger wires disconnected to protect the ECU). This takes away the compression loads on the starter. If the test figure improves its a starter issue.

Don't forget you should crank the engine until you get a steady compression reading. I was always told three to five compression pulses. This (IMO) overly basic explanation says 10 times. https://www.wikihow.com/Do-a-Compression-Test

 

[The Panda Nut]

Not much to add as tests already done as suggested and the battery is fine and starter sounds fine. The smoke is a puff of bleish / white oil smoke. We have a catch can fitted as there is quite a helping of sludge in the winter. In this dry spell there is very little water caught and only a whisp of oil, not enough to give much concern. Water consumption is zero and the car seems to have plenty of power.

All the plugs looked very similar and no signs of anything untoward there as far as I coild see.The spark plug problem is a pain and I have decided to leave it a while longer and then have the cam belt water pump etc done and the head off at the same time so the valve stem seals can be done, or the head reconditioned if required, or.... if I can find one a replacement car found. Costs of that for anything better look prohibitive so an overhaul looks a better bet. I may test the other car and see how that compares as engines should be pretty well the same.

My other idea is to buy a 2ndhand engine as I have seen some very low mile engines c.2015 or newer for just a few hundred pounds on e bay. I could do the clutch and check the whole system mechanically, might even buy a damaged vehicle if I can find one that seems OK.

 

[koalar]

Looks well down on compression to me

Let’s call it 150 compared to 200

That’s a difference of 1/3 are you sure it’s timed correctly

206 PSI seems to be about the average (14.2 bar)


Yes the spark plugs are a pain. They don’t screw in straight but in a kind of V configuration, I am surprised we don’t get more cross threaded

I have owned three Pandas and one punto, when they are running correctly there should be no build up of moisture or oil in the inlet manifold summer or winter although my smallest journey will be 3 miles and the car driven at least once a week.

 

[DaveMcT]

Smoke on start and between gear shifts is valve stem seals. However, low compression is far more likely to be bores and/or piston rings. Prove that with a squirt of oil down the cylinder before doing the compression test. If numbers improve, its rings. If numbers stay the same, it's valves.

My 100HP has 125,000 miles and no oil smoke. It does use a bit of oil when driven hard but they are known for that. Wife's 1.2 Dynamic has 80,000 mostly town miles and is doing just fine. Oil level hardly drops between oil changes. The clutch is getting heavy so that's looking due and I've just noticed the infamous coolant pipe is looking crusty.

 

[The Panda Nut]

Looks well down on compression to me

Let’s call it 150 compared to 200

That’s a difference of 1/3 are you sure it’s timed correctly

206 PSI seems to be about the average (14.2 bar)


Yes the spark plugs are a pain. They don’t screw in straight but in a kind of V configuration, I am surprised we don’t get more cross threaded

I have owned three Pandas and one punto, when they are running correctly there should be no build up of moisture or oil in the inlet manifold summer or winter although my smallest journey will be 3 miles and the car driven at least once a week.

I dont believe I have such a big compression loss as the car is quick. We have a 2014 Euro 5 car and the 2011 is on a par with it performance wise is not better. I think the test was not right or the gauge is badly calibrated. Due to its fittings it was not possible to crew it in tight as I cannot get to it so it was relatively lightly screwed in, nbut the asme in each cylinder. I am going to repaet the test with the push on fitting and see what that shows, and I will test the 2014 car when it gets its service which is imminent. The car did very very few miles under its first owner so may well have a polished bore problem. Oil consumption is negligable. I last filled it with Petronas Syntium and have been concerned with both cars draining and then rattling on start up which was not a problem previously. This car was changed for Castrol Edge 5/30 at its last change and does not suffer the start up rattling much since while the 2014 one still running Petronas Oil rattles like mad after 48hours of standingn so I shall never use this oil again, normally I run Mobil 1 and have never has any oil or indeed engine wear issues on any carusing it. I was lead into hte Syntium trap by S4P who ere selling as a service item and I thought it woud be fine as its a Fiat recommended oil. I see there is a rear ended 2016 Panda for sale whole for £1700 on the net. It looks very repairable. I was thinking may be of buying it swapping engines, and then selling it on either repaired or not, or just keeping it for spares. If I PX our 20111 car and chuck another £2k at it I suppose we would have a budget of £4250. Trouble is that doesnt get us much further forward.

 

[DaveMcT]

These engines are happiest on 10w40 semi synthetic. They do not need (or want) anything more sophisticated. Super thin oils like Mobil 1 get burnt so the level can quickly drop dangerously low. The start up rattle is a sign your engine is getting trashed. Mine make no abnormal noises on engine start - hot or cold and has always had ordinary 10w40 semi synth.