[fixed] [flooded from short start] now barely idles (ES9J4)

[8Jb9]

I had 3-4 squares on the oil indicator, and plenty of room on the dipstick, so I topped up the oil with 2-3 dL yesterday. This morning I checked the dipstick and it was 1/2 on the front side and 3/4 and the backside, and the digital gauge was not alarming.

When I started it this morning it barely ran, and it was definitely burning oil. I'm unsure if it's because of an overfill-situation, or if it's my mistake of not running the engine after the top up which has allowed some of the oil to seep into the cylinder. Any advice? I've got PP2000.

It was my impression that it had difficulties cranking the second time I tried as well.

[markw]

"2-3 dL" ??
Do you mean 2/3rds of a litre or 2 to 3 litres?
The first one sounds ok, the second doesn't! The dipstick on my ES9J4S is notoriously bad for getting a clean, distinct reading from it and I have to wipe and dip it a few times to be sure. I never rely on the dashboard display only.
If you've overfilled, you're best course of action would be to drain it all immediately and put the correct amount back in.

Don't run it any more till you're sure you've definitely got the correct volume of oil in there.

[8Jb9]

I wrote desiliters, yes. 0.2 - 0.3 L.

Total oil in it including top-up since oil change is 5.5L (equivalent to 5.2L because I can get more oil out with suction drain than gravity), and it has driven a bit over 5000km. The oil consumption seems similar to what I had at last service (0.5-1.0L per 10.000km).

I always run the dipstick twice.

[8Jb9]

No faults on the engine ECU - I had expected 'misfire'. Maybe because I've only allowed it to run for <~10s.

The dipstick is well below max, average of front and backside is in the middle of it, and the electronic gauge shows 4 of 6.

I'm thinking that I should remove the spark plug on cyl 1 and see if it is contaminated with oil. Any other suggestions?

[crackpotterpig]

as previously said dont rely on the dash display for oil levels, sounds like you have def overfilled, make sure you are checking the oil level on a level surface double check and post a piv on here if possible showing the dipped oil level on the dipstick.

[steve_earwig]

If it helps:

XFZ ES9 (Suction draining) 5.25 dm3 2,0 dm3
XFZ ES9 (Draining by gravity) 4.75 dm3 2,0 dm3

[8Jb9]

Thanks for staying with this issue.

I don't rely on the digital meter, however it has been matching the dipstick rather well so I found it relevant to mention. Image of the dipstick included (20min rest after cranking), and the digital gauge is at 4 of 6. With the numbers steve presented (and also the ones I go by) I am rather confident now that it isn't an overfill.

dipstick.jpg

I'm not sure where the puff of oil came from, when sniffing the exhaust pipe I can only smell petrol.

When I looked under the engine cover I could see oil from the filler port as I had expected. The rubber gasket on the cover isn't flexible enough to make a good seal. Some of this oil had gone into cyl #1 ignition plug recess. There was no apparent liquid in the tube within which the actual plug is, but it was golden at the bottom, as if 1 drop could be there. I tried to clean it all up as best I could before I put it together again - all without removing the plug itself.

coilpack.jpg

When I cranked it afterwards it behaved just like when the TDC-sensor died; it cranked without hesitation but didn't have any ignition. It didn't help to floor it during cranking (anti-flood mode). PP2000 showed the engine ECU as having no faults the first time in the morning, and then afterwards didn't respond.


Other than checking if the engine ECU's got some codes after removing the coil pack and perhaps checking under spark plug #1 I'm not quite sure how to proceed.

[steve_earwig]

The ecu didn't respond? Maybe that's where the fault is I nearly asked if any oil had spilled but then I thought I'm the only person that careless...

I thought oil was an insulator but I've heard of misfires when too much ends up around a plug. Still, the other 5 should be ok but it's not firing at all. Not that I'm one to believe in coincidences but I reckon you should investigate this like any other fault, treat the Amoco Cadiz as a red herring.

[8Jb9]

Engine oil contains additives and suspended particles which makes it conductive. I think that one or a couple of teaspoons of oil got past the oil cap/cover plate O-ring, and a lot of this ended up in the water trap in the square recess of spark plug #1. In the cylindrical hole for spark plug #1 there may have been a droplet. I don't know if this can have seeped past the threads (capillary), or if it is tight enough to prevent this.

The engine ECU did throw me off a bit - it doesn't explain the initial symptom (single cylinder misfire on two individual engine starts within 2 minutes, with total run time less than 10 seconds).

But the ECU-issue does fit with the later zero cylinder ignition symptom. I'll recheck the connection to the ignition coil, which I had to disconnect to remove the coil assembly. Also I noticed the the coil assembly had cracks in the plastic casing - but I only touched the front-most assembly (cyl 1-3), cyl 4-6 are completely untouched.

Other than re-checking with PP2000 if I get a reply from the ECU, how do you think I should proceed to weed out the goblins?

[crackpotterpig]

your right about the dipstick oil level the extra bit is just whats been pulled up the tube as you pulled it out, the oil level is somewhere in the middle which is fine.
I think its just coincidence that after you have topped up the oil it has started mis firing and then wouldnt start.

[8Jb9]

I believe that my two short engine runs with misfire caused a bore wash as the petrol from the rich mixture during starting evaporated. Would explain the loss of resistance during cranking this evening.

What is the safest way to recover from this?

[steve_earwig]

Safest? I dunno about that. I'm not too hot on modern engines but the old checks used to be: compression, fuel, spark Worryingly you seem to be saying the engine seems to lack compression? I think you need to check the cam belt so we can all exit panic mode. Then you need to see if the ecu is still sulking.

[8Jb9]

Easy on the panic mode. I'll check the belt in the afternoon, but it's not that. It's a year old and replaced by Peugeot.

Symptoms are identical to when the TDC sensor was replaced last year, with the engine cranking with ease.

Saturday: moved the car 5m. Waited, moved it 5m back in the garage. Sunday, topped up oil without trying to start. Monday, started immediately, but didn't run on ca. 1 cyl. Stopped it as soon as it felt wrong, then restarted (key fully off/fully on=priming fuel pump and wetting intake). Next try Monday afternoon with a blurp initially, then easy cranking. That's four engine starts too short to leave rich idle.

I think you were right to say that the oil spill was a red herring, and that bore wash could perhaps also explain the initial misfire.

[8Jb9]

Actually, can someone with knowledge of the engine ECU confirm that *our* ECU supports 'clear flood' mode, where it cuts fuel during cranking if the throttle is kept wide open? The alternative would be to take the fuel pump fuse, I believe.

If my hypothesis is right I need to re-wet the cylinders with oil during cranking without adding more solvent (petrol) to the cylinders.

[8Jb9]

Problem solved. Below is a quick rundown of the issue:

Symptoms
Engine misfires, hardly fires, and/or eventually doesn't fire at all. Cranking until the battery is flat doesn't seem to help.

Car worked flawlessly yesterday.

Prerequisites
Quick starts and shut downs the day before, e.g. from shunting (5m) or from resetting the economy mode. In my case >=2 starts.

Actual problem
Car is badly flooded. It may be subject to cylinder wash, but I'm unsure of this. Either way the problem doesn't disappear from waiting a few days. Luckily the solution for either of those two problems is the same.

Solution
A second car with jump leads is probably necessary, as this extended cranking will run the battery down too far, and the starter will loose its oomph. Connect the leads as early as possible, as then there will be basically no (electrical) potential difference between the cars.

Pull the fuel pump fuse (#25 in the engine bay). Throttle should be feathered back and forth, most effective seemed to be around 70%. A bit more and you'll loose all tendency to fire from out of nowhere (inefficient flood clear mode, probably). Crank until it starts firing (weak 'floof'). Crank in intervals, as the starter cannot take such extended cranking without overheating. It will probably need a total of a minute 'dry' cranking before it seems to work.

Refit the fuse and feather the throttle until it starts. Again around 70% seemed to work for me. If it takes more than 10-15 sec before ignition improves it's still flooded/bore washed and you need to go back one step. Hold idle manually when it starts for a little while (in my case ~1500rpm) to allow any excess petrol to be burned off.

Why does this happen
The ES9J4 runs extremely rich on cold starts. The J4S apparently less so. Accounts from the coupe-forum state that petrol can clearly be smelled during the first few minutes after starting, and the same is true for mine. It's just the way it is programmed.

When doing the quick starts - it's even worse when turning off the ignition between starts because of inlet priming - an incombustible mix will eventually form. If cylinder wash is happening this is when it starts.

How to avoid
Let the engine run for at least long enough to burn off the inlet priming, and even better allow it to depart rich idle. In my case that means waiting until idle is back to ~650rpm.

If such bad starts are unavoidable don't let it sit until tomorrow. Start it properly and go for a drive before going to bed - it won't start again tomorrow if you don't.