what happens when you have too much oil in the engine

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gwest
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what happens when you have too much oil in the engine

Post by gwest »

I recently bought a 2007 Peugeot 207CC with the AL4 auto gearbox with 130,000 km on it, that was reported as having low compression on cyl 1. It turns out that the oil level was about 90mm above the top mark - I drained 7.5 litres from it. There was no sign of water in the oil. You have to wonder. Taking the engine cover off revealed that exhaust valve no. 1 (transmission end) had lost its intermediate rocker (it was lying loose nearby) and was not fully seated. The cam timing was advanced, more so for the exhaust, but I am only guessing that it was about 5 degrees out. I have yet to remove the engine from the car but will take off the cylinder head in due course. What sort of damage should I be looking for?

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xantia_v6
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Re: what happens when you have too much oil in the engine

Post by xantia_v6 »

Which type of engine is it?

It is possible that there is no internal damage other than the rocker.

gwest
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Re: what happens when you have too much oil in the engine

Post by gwest »

I should have said the engine is the EP6 non-turbo petrol 1.6, so it has the twin VANOS as well as the complicated variable valve lift on the intake valves. At least it doesn't have direct injection!

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CitroJim
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Re: what happens when you have too much oil in the engine

Post by CitroJim »

Too much oil in a diesel engine can be very dangerous... The excess oil can get sucked up into the combustion chambers and the engine will start using this oil as fuel - in a very uncontrolled way! It's likely to result in a destructive runaway as there's no easy way to bring the engine to a halt. the only way is to totally starve it of air and trying to do that can be very risky - for a variety of reasons...

In a grossly overfilled engine it's possible for the crankshaft webs to dip into the excess oil, being too high in the sump. This will cause huge amounts of drag and a very noticeable reduction in performance... Also, the overfilled engine is likely to be very smoky as oil is drawn into the combustion chambers...

In general it's better to run and engine slightly underfilled than overfilled... As long as there's oil visible on the dipstick between the high and low markers it has enough...

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Re: what happens when you have too much oil in the engine

Post by Hell Razor5543 »

I heard (from a friend who was a mechanic) of a case (decades ago) where somebody decided to service their car, and did not either know what they were doing or check how to do it. When they had finished servicing the car they were bemused to find that the car would not start; in fact it would barely turn over. After not finding anything wrong they called my friend, who found that the engine was FULL to the filler cap with oil!

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CitroJim
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Re: what happens when you have too much oil in the engine

Post by CitroJim »

Hell Razor5543 wrote:
02 Oct 2020, 18:02
I heard (from a friend who was a mechanic) of a case (decades ago) where somebody decided to service their car, and did not either know what they were doing or check how to do it. When they had finished servicing the car they were bemused to find that the car would not start; in fact it would barely turn over. After not finding anything wrong they called my friend, who found that the engine was FULL to the filler cap with oil!
:lol: :lol: :lol: Love it!

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Re: what happens when you have too much oil in the engine

Post by Gibbo2286 »

My brother had a similar episode, he drove a Ford Thames Trader for a greengrocery wholesaler, a V8, he had a new driver's mate, they loaded the truck and he told the mate to 'to up the oil, while go and sign out.' , when he came back and fired it up they were swamped in oil as it blew the lot out from under the engine cover into the cab. :)

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Re: what happens when you have too much oil in the engine

Post by Steve Walsh »

A couple of tales from me, 1st on a serious note, I worked for many years as a marine engineer, a lot of work with V8 Chevrolet petrol engines as used in many boats, Had a few customers that had overfilled the sump and then found a huge drop in power, caused by the drag of the crank in the oil, but also the oil becomes airreated ( spelling ) Think fizzy.... which than causes hydraulic valve lifters not to operate correctly. as above comments a little under full is better....

Now an amusing one
A very good friend of mine was a Pursuit trained motorway cop, One day he turned the engine on at the start of the shift and the dash reading says oil level is low, so he gets a jug of oil and pours some in, all the time checking the dash reading, after putting in many litres and no change in the reading he was called out on a job, and thrashed this motor down the motorway, with a cloud of smoke following him then a huge bang as a con rod came through the side..... When asked about the oil level it was discovered he didn't turn ignition off and back on to get a new reading, After that all oil top ups had to be done by the garage..... My mate had put around 15 litres in his cop car....... !

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Re: what happens when you have too much oil in the engine

Post by Sloppysod »

I bought a Cortina Mk3 back in the early eighties for scrap, owner said the engine had blown as it was smoking heavily. I got it home drained out alot of oil, then started the car, after a couple of minutes, no smoke runing sweet a s dre.....Ford, he had changed the oil without draining the old stuff...................sold it on for a very good profit.
CitroJim wrote:
02 Oct 2020, 17:47
In general it's better to run and engine slightly underfilled than overfilled... As long as there's oil visible on the dipstick between the high and low markers it has enough...
The oil level myth. there are two marks on a dipstick, Min and Max, and that is exacly what they are a minimum an maximum oil level for that engine, so many people fill a car to the max level..... because they can. I always aim for just over half way between the two marks.

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Re: what happens when you have too much oil in the engine

Post by gwest »

Well, I'm not sure if the overfilling is now my main concern. After pulling off the head I discovered that both exhaust valves on no.1 cylinder (gearbox end) had dropped valve seats. At least they had not disintegrated yet. Removal of the pistons showed scuffing on the thrust face such that I could get a 0.005"feeler gauge between the piston skirt thrust face and bore on no. 1 cylinder, 4 thou on no. 4. The bores looked ok but I don't have the skills to measure the bore accurately (I can check for out of round). The hardness around cylinder 1 was 100-103 Brinell.
My newly acquired 2007 Peugept 207CC VTi with the AL4 auto transmission has covered 130,000 km. It has VIN is VF3**************[VIN obfuscated, can be read by forum staff], and Engine no. 0054186/ 10FHAN/ PSA5FW my questions are:
1. Should I just have the errant exhaust valve seats replaced in no. 1 cylinder, or all the exhaust seats, or the whole 16?
2. Is the piston wear sufficient to necessitate replacement? The gudgeon pins don't use circlips to hold them in place so I would have to get an engine reconditioning place to use heat to fit the new pistons to the conrods. If they need to be replaced what part nos am I looking at?
Just as well this is a retirement project aimed at staving off dementia!

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CitroJim
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Re: what happens when you have too much oil in the engine

Post by CitroJim »

gwest wrote:
15 Oct 2020, 11:31
1. Should I just have the errant exhaust valve seats replaced in no. 1 cylinder, or all the exhaust seats, or the whole 16?

I'd take the advice of a trusted head reconditioner after a critical inspection by the reconditioner...

Given the ehad damage and the piston wear, a replacement engine from a scrapyard may be the better option in the long run...

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Re: what happens when you have too much oil in the engine

Post by gwest »

I need to correct my previous post. The Haynes manual described the petrol engines as having interference fit gudgeon pins - turns out my petrol EP6 has circlips, which makes replacing pistons a lot easier. And yes Jim I had given thought to a second hand engine but I will see how the estimated repair costs stack up. I presume for my valve seats to have dropped there has been severe overheating, but am comforted that the head has not annealed to the point that it is scrap. Is there anything about these engines that indicates that the cylinder furthest from the water pump runs hotter? The coolant certainly has to work at getting through the narrow passages in the block around the other cylinders. And why on earth would they number the gearbox end cylinder as no. 1?

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CitroJim
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Re: what happens when you have too much oil in the engine

Post by CitroJim »

Good to hear the head is not annealed... A dead give-away is if the old head gasket fire rings have embedded themselves into the head face...

Am I right that you are doing the engine rebuild your self as far as possible? If so, then I'm following with great interest :)

Certainly circlips on the gudgeon pins makes life a lot easier...
gwest wrote:
17 Oct 2020, 12:08
And why on earth would they number the gearbox end cylinder as no. 1?
Because they're French :lol:

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Re: what happens when you have too much oil in the engine

Post by gwest »

It might be more appropriate to alter this thread to that of engine rebuilding, since that is now going to be the challenge. One unexpected problem was that the inlet camshaft had suffered serious corrosion on some of the lobes, to the point that it will need to be replaced/repaired. Since it was on the exhaust side that the valve seat had dropped a friend (who can weld) and I made an angle iron frame to to hold down the exhaust camshaft while removing the caps, to avoid any possible complications with the bolts that were under pressure. The Haynes manual uses this technique for the turbo motor to remove both their camshafts, but does not recommend that owners try to work on the non-turbo VTi cylinder heads, because of the strong springs associated with the variable lift mechanism. However, there are YouTube videos showing a Brit using a couple of ring spanners, and Russian (?) with a homemade tool, to give an idea of how it might be done. The Russian method worked fine although I found it desirable to clamp the head to the bench while holding the tension on the springs and removing the retaining bolts. That made for an easy one person operation. The removal of the inlet camshaft is then easy because it is under no tension. I wanted to check the inlet valves and that meant removing the retainers for the eccentric shaft, but I discovered that the shaft would not come out, being held in at the sensor end. Before the newtis.info site was closed down (under pressure from BMW) I had gleaned that it was forbidden to remove the bearing bracket that would allow removal of the eccentric shaft. I have no idea why- they said it would damage the cylinder head. That makes it more difficult to release the valve springs, because access past the eccentric shaft is tight. I made a cutout in a length of 20mm pipe and used it as an extension of my valve clamp tool, and eventually released all the inlet valves. My reading of the web literature suggests that these early EP6 motors were susceptible to both inlet and outlet valve seat drop, but at this stage I am thinking I will only get the exhaust seats replaced. I am hoping that a bit of grinding paste is sufficient to clean up the inlet valve seats.