Mi16 Oil Surge Problem

[Bally 4]

I think we have been all messing around these engines long enough that we should be able to come up with

 

1. The reason for the oil problem under cornering

2. The solution.

 

My engine has been rebuilt from scratch- new everything. Oil pressure is good with a new Autometer gauge.

 

25 psi on idle when to operating temperature, over 50 psi at 3000 rpm hot.

 

Oil and filter is changed every 2 months- Oil is still clean when removed. I use it to change the oil in my other pug.

 

I have on the aluminium sump with the spacer plate. My car takes close to 6 quarts of oil every oil change. I even add extra to help the surge problem.

 

Whenever I go into any long bend while accelerating I find my oil pressure gauge drops from 75 psi to about 40 psi, and may even be lower. Oil light never comes on, but still its scary.

 

To the point that I dont trully enjoy the car as I should cause I find now that I dont accelerate around corners at all now, I accelerate on teh sttraight and then come off and cruise around corners and then back on throttle. I dont take my car on the track here.

 

Need definate answers to the cause and the solution.

[C_W 3 1 Cars]

It seems to be head drainage. Sometimes it happens really easily.

 

I'd say for road use buying the Peugeot bolt in baffles should help (oil pump baffle, centre baffle, and fitting the windage tray if possible but not sure if it fits with the spacer plate).

[Bally 4]

I have on the S16 sump with the little flap/gate.

 

I also cant phantom a head holding six quarts of oil??? Possible???

Edited May 8, 2006 by Bally

[C_W 3 1 Cars]

Not sure then. It can seem a little wierd how easily it can "surge" sometimes and some suffer a lot more than others which is also very strange.

 

Mine has a centre baffle (not trap-doored), oil pump baffle and also a top plate on the side opposite the oil pump. It still drops on track etcs but the light no longer comes on which was a problem when I first started tracking it.

[Bally 4]

I dont get a light, but it has me worried. I can count the number of Mi16 engines here in Barbados on one hand.

[Rob Turbo 3]

I had an idea that may help solve this, theres lots of space in the head for oil to sit in instead of draining straight back to the sump, I understand this is why the gti6 doesnt have these problems (because the big space isnt there!)

 

So, my idea is this, lots of liquid metal to fill this gap, obviously you will need to put maybe some steel plate in to stop it going into the valve springs

 

This way oil wont collect in the head and should stay where its needed, sort of like putting a brick in your toilet to save water!

 

(go on, flame away!)

[smckeown 1]

The OE oil warning light only comes on at ~7psi. By that time your engine is already in serious trouble. I'm led to believe a sensible oil pressure warning light should come on at 35psi, and thats what i set my old one to. Therefore if your getting 40psi in a road car on a fresh engine i'd be woried.

 

Would be good to see what other people think of this

[B1ack_Mi16 67]

Not sure then. It can seem a little wierd how easily it can "surge" sometimes and some suffer a lot more than others which is also very strange.

 

Small differences in the casting of the heads might result in different oil-return channels.

Which again will influence how fast the oil can drain back.

[Jonmurgie 2]

1. Cr&p design

2. Dry Sump

 

[Miles 331 1 Cars]

It is a bad design, think of the 8v engine can drain without too many problems where-as the 16v has the exhaust cam + some head sticking behind the oil drains at a angle.

The crank angle of the 1.9 engine doesn;t help the big ends either

[Bally 4]

But again, this post is heading in the direction of maybe this maybe that. Its as tho we got this engine from peugeot only last week, its a new design and we have broken any yet.

 

We should be at a point where someone should be mass producing the solution, and selling cheap, and no one in the world with a mi16 engine would ever phantom putting up an engine without it..

 

The first great idea I have heard so far is the one about filling up the head, that is what I have been thinking about for a while now, HAve a bare head out to start looking at ideas for filling up the head this weekend. The design should be a bolt in one or a wedge fit one so that it can be easily produced, continues to allow oil to move around and can easily be retrofitted. .

Come on guys, lets all work on this and finally put it to rest. They are too many mi16 dead because of this problem.

 

All the designers and engineers on here. Lets get this one problem sorted once and for all.

 

I am begging the mod to make this a stick, and turn this into 10 pages of, maybe an accusump will work, or maybe dry sump will work, or maybe this maybe that.

[rich_w 0]

I think the last page or 2 of this thread has the cheap solution:

 

http://forum.205gtidrivers.com/index.php?showtopic=30605

Edited May 9, 2006 by rich_w

[Phil 0]

If the problem is oil not draining from the head fast enough under gravity then how about forcing it out? You could do this by either pressuring air space in the head with a closed recirculating breather system (although the consequences of the pressure acting upon the oil entering the head would have to be taken into account - higher pressure oil pump spring?)

 

Or you could suck/pump the oil out of the head but this would be a bit more difficult as you would need to drill somewhere in the head to do this! You could possibly fit small metal tubes around the head exiting via the rocker cover to a pump and then to the sump to pick oil up out of the head in much the same was as oil is taken from the sump.

 

Obviously they are just some suggestions off the top of my head

[petert 554]

What's wrong with 40 psi? It's more important to have flow than pressure. That's why the 2L 26T sprocket upgrade is such a good option.

[veloce200 3]

What's wrong with 40 psi? It's more important to have flow than pressure. That's why the 2L 26T sprocket upgrade is such a good option.

my brother works for BMW and says on the latest engines they have electric pumps to scavenge oil from the heads - so there's the answer guys !

[findlay 0]

I also cant phantom a head holding six quarts of oil??? Possible???

 

But its not just in the head, the engine is full of corners, channels and galleries where the oil flows... The problem comes when there isn't quite enough oil in the sump for the pickup to reach. This is caused by (easily?) 2litres build-up in the head etc etc.

 

Various solutions have been suggested but only dry-sumping (and as a last resort solid lifters with a restrictor in the feed to the head) is likely to work. Somehow I doubt this is the answer you were looking for...

[Ahl 4]

Stop: all engines will suffer oil starvation/surge to some degree and dry sumping is obviously the fail safe way to stop this.

 

But the simple fact of the matter on mi16's is: the head holds too much oil, especially when moving a certain way, the oil can't drain back very well and the sump ends up without enough oil to be picked up, especially when it surges to one side.

 

Possible solutions:

 

Dry sump

Fit solid lifters and restrictors so less oil in head

Decrease volume in head so less oil can be retained

Add additional drains to head

Increase amount of oil available

Fit sump baffles to keep oil around pickup

 

I think peter explains it well here, and he takes the additional step of making the sump and pickup deeper, I guess so even more additional oil can be added.

There's been plenty said on this forum about 16V oil control. Here's how I do it, after fitting a 15mm spacer to a trap door alloy sump (either 1.9L 8V or 2L) and topping up with 6.5L of oil.

 

A ring, the same shape as the pickup is cut out of aluminium plate on a CNC mill. The plate is then TIG welded to the pickup. Socket head cap screws are used to retain the screen and cover. This allows complete cleaning of the pickup in the event of any more mishaps.

 

If you're good enough to get oil surge after using this setup, together with a windage tray, you need a dry sump solution. It's a tried and proven race car solution.

 

You can purchase either just the ring, or a completed pickup sub-assembly.

 

Is that simple enough? Can people who are not mechanically minded understand the simplicity of this? Will you now stop going on about f***ing dry sumps as if its the only solution to this very practical problem?

 

I think we have been all messing around these engines long enough that we should be able to come up with

 

1. The reason for the oil problem under cornering

2. The solution.

The problem is the very few people who actually have been messing with these engines, know what they're talking about, and have practical solutions are FAR outweighed and seemingly ignored by all the f***ing internet mechanics on this forum who love to talk s*it and keep on repeating it until they believe it themselves.

[findlay 0]

lol... Indeed! (calm down Ahl!!! )

 

Peter's solution is simple (it is certainly very simple logic and reasoning to how it works after all the head can only hold a certain amount of oil before it would be totally full) but I'm keen to see how Jon's fitting of the dry sump kit goes.

 

I think Martin (crf450) had a different approach to the problem - but he's using an S16 lump

 

I think the only point worth mentioning regarding anyones internet mechanic abilities is that yes, there is a serious flaw in the Mi engine design, but its not the end of the world and when it comes to the crunch (no pun intended) everyone is still entitled to an opinion on the best/easiest way of curing the issue. There are means to combat it.

[Kitsune 0]

Can anyone give me some info on the solid lifters and restrictors? This is something I want to do in the future but know very little about how it all works (and the reason for solid over hydraulic). Also, why the need for the restrictors?

 

Anyone actually use solid lifters and find this helps with the surge issue?

[saml666 0]

Can anyone give me some info on the solid lifters and restrictors? This is something I want to do in the future but know very little about how it all works (and the reason for solid over hydraulic). Also, why the need for the restrictors?

 

Anyone actually use solid lifters and find this helps with the surge issue?

 

Not so much an answer, just that I had the conversation yesterday with the guy whos sorting my valve re-cutting ... A passing comment he made was that he'd done it on an Mi16 a while back and it ended up really noisy as the standard cams had no "quietening ramp" so clattered like hell (mech lifters can be noisier anyway but this was exceptional). Do any of the aftermarket cams have profiles to suit mech lifters better? I know the VW stuff usually comes in both "flavours".

 

Incidentally, I'm going to start by drilling Cartooner's extra hole to divert oil drain from above the pump chain and baffle the sump.

 

Oh, and, erm, pick that gearbox up

 

Sam

[rich_w 0]

Hi Sal666,

 

Another cheltenham'er I see

 

Who's doing your valve re-cutting? Are they in the cheltenham area?

[petert 554]

The restrictor has a similar size orifice to the one-way valve it replaces. So a similar amount of oil will pass through. The only difference is the amount of oil held in the hydraulic buckets - 16 x 5ml? Hardly significant. Oil will still hang around the exhaust side of the head. You either have to dry sump it and scavenge the head, or put more oil in a wet sump to compensate.

 

A passing comment he made was that he'd done it on an Mi16 a while back and it ended up really noisy as the standard cams had no "quietening ramp" so clattered like hell (mech lifters can be noisier anyway but this was exceptional). Do any of the aftermarket cams have profiles to suit mech lifters better? I

 

fitting solid buckets to a hydraulic grind is always going to be noisy, and possibly short lived, for that very reason.

 

Anyone worth their salt can offer a solid grind for an Mi16. I have a couple I can offer.

[Kitsune 0]

Cheers for the info petert. The pug is purely for track use so noisey bits aren't too much of a problem for me.

 

Sam, when you're ready mate!

Edited May 14, 2006 by Kitsune

[saml666 0]

Hi Sal666,

 

Another cheltenham'er I see

 

Who's doing your valve re-cutting? Are they in the cheltenham area?

 

Alright Rich, its Steve Baker in Churchdown - nothing gets done quickly even if he says next week ;-) but his work is absolutely first class with total attention to detail.

 

He's on 01452 712321 (Chosen Engineering)

[Guest Cartooner]

But again, this post is heading in the direction of maybe this maybe that. Its as tho we got this engine from peugeot only last week, its a new design and we have broken any yet.

 

We should be at a point where someone should be mass producing the solution, and selling cheap, and no one in the world with a mi16 engine would ever phantom putting up an engine without it..

 

The first great idea I have heard so far is the one about filling up the head, that is what I have been thinking about for a while now, HAve a bare head out to start looking at ideas for filling up the head this weekend. The design should be a bolt in one or a wedge fit one so that it can be easily produced, continues to allow oil to move around and can easily be retrofitted. .

Come on guys, lets all work on this and finally put it to rest. They are too many mi16 dead because of this problem.

 

All the designers and engineers on here. Lets get this one problem sorted once and for all.

 

I am begging the mod to make this a stick, and turn this into 10 pages of, maybe an accusump will work, or maybe dry sump will work, or maybe this maybe that.

 

 

Even if You would fill up the head like You say, You would not overcome the problem. Also remember that the oil is needed here to cool and lubricate things too. The problem is that the channel on the distribution side ends up just above the pumpgear in a small chamber that is easily filled up with oil when the oil is forced to the righthandside of the pump by centrifugal forces. When this channel can't drain to the sump it gets filled up with oil. At that point the channel no longer flows and the oil will pile up in it and flood the head. Eventually the pump-pickup will fall dry.

 

If the cause would be that the hydraulic lifters use too much oil than the solution would be as simple as filling the sump with extra oil when cold, thus compensating for this.

 

No, I am pretty sure the problem is in the spot where the drain channel on the distr.side ends. This is why I drilled an exithole that faces the sumpside instead of the oilpumpgearhousing, as to maintain oil flow back to the sump when the oilpumpgearhousing gets filled.

 

Just ask Yourself why it is only on lefhandcorners of prolonged duration that the problems occurs mostly. Because the oil in the sump is forced to the righthandcorner which starts a string of problems!. The exit of the oil passage on the flywheelside is located in a spot where it will keep on flowing under all conditions.

 

So: 1. Make sure the righthand oilchannel keeps flowing under all conditions.( Drill a hole like I did)

2. Add baffles to the sump, so the oil stays near the pick-up.

3. Keep oil-level to the max or slightly over at all times.

 

cheers