Oil filter and seal woes.

[Thegurgan]

Since my last post over a year ago, my mini has come along pretty nicely. And I can report that it runs like a dream. But tonight, I experienced a problem that I would like to have someone weigh in on. I was parked downhill, and started the car up. When I started to back out of the parking space, I felt a sudden loss of reverse propulsion, and I heard a strange noise from the engine compartment. I immediately shut the engine off, and walked around to investigate. There was oil puddling on the ground, and the grill had oil sprayed through it near the alternator area. I removed the grill, and I found that the oil filter o-ring was dislodged and bulging from the housing. I took the filter housing apart and inspected the o-ring. I found no damage, and placed it back in the oil filter base. The housing was a little looser than I wanted, so I added a washer under the bolt head, and reinstalled the entire filter assembly. When I started the car, after adding oil, the engine ran great. I inspected the oil filter housing, and saw no leaking oil. I placed the car in reverse and began to back out of the space, and again, the seal dislodged, and oil sprayed from the filter housing. I was using the thinner of the two o-rings that come in the filter box. And I haven't yet replaced it with a new one. (Probably will go with the thicker one this time and remove the extra washer)

I know when these cars are placed in reverse that the pressure at the filter is increased. But I haven't experienced this problem before tonight, and I've been daily driving the car for about a week and parking in the same space with no issues. Has anyone else experienced this? Is it most likely an o-ring issue, or is there something else to suspect? I couldn't see any damage to the housing, and I have a diagram of the proper assembly of the parts. And when I say it sprayed oil out, I mean it shot out of the front of the grill and poured out of the housing.

Also, here she is. My baby.

[jockduck]

Hi, Yes some people do have problems with filter sealing and I don't really know why, I guess you have to be there. To state the obvious the seal should not get pushed out it should be safe in its groove in the filter head, one thing I have come across in the past is previous mechanics not removing the old oil seal rings before adding a new one, are you sure there is only one seal in the groove?
Jock

[Thegurgan]

Thanks for responding Jock. Yes, I'm sure that there is only one seal. I took it out to inspect it, and then checked the groove where it goes to ensure it wasn't damaged.I read somewhere that someone suggested that the valve body in the transmission could be stopped up a bit, causing the pressureto be unusually high in reverse. But I suspect thatit's just that I'm using the narrow seal and should move up to the wider one.

[limby2000]

Hi,is it the o ring at the nut end under the washer,or the cup end (really big one)?.

[Thegurgan]

This ridiculous thing.  

[mikerotherham]

I could only get the thinner of the 2 o rings to fit comfortably in the housing last time I changed the oil.

Have you torqued the filter canister up sufficiently?

It says it should be 19 nm in the Rover Manual

[limby2000]

Feb 20, 2016 4:14:27 GMT Thegurgan said:

This ridiculous thing.  View Attachment

Surely thats a hula hoop!

[Thegurgan]

Something is terribly wrong here. I removed the entire filter head from the gearbox and verified that its passages are clear. I made absolutely certain that the filter o-ring (see image above) was seated properly in the groove of the filter head. I verified the placement of the filter, circlip, filter washer, spring, and filter cup. I then installed the cup onto the filter head to ensure that the cup seated properly against the o-ring. Then I installed the entire assembly back onto the gearbox, and tightened everything very tightly. And I still got oil spraying from the cup where it seats against the o-ring. I took it all apart again, checked the cup for a warped rim, reassembled with a lock washer and a flat washer under the bolt head, and put the entire housing back onto the gearbox. This time it sealed for about 15 minutes, and then again started to spray oil out. What in the everloving hell has happened to my mini? I have never had an issue with this assembly before, and now it's unsolvable. Something has changed dramatically causing either an increase in pressure at that point, or the laws of physics no longer apply to my car.

[jockduck]

Yes it sounds like hell, I have never been so unlucky, couple of things, you could do a pressure test to make sure things are within the bounds normality, also is it possible the long bolt is becoming thread bound before the bowl is fully pulled up to the head seal? one last thought, what is the other end seal like the one that sits under the thick washery thing, it should compress fully so that the bowl sits against the washery thing.
Best of luck
Jock

[Thegurgan]

When I bolted the cup back against the filter head, I gripped it and tried to twist it. Before I added the washers, it would spin (albeit with a bit of force). After adding the washers, it would no longer spin at all. I took this to mean that I was getting sufficient pressure against the o-ring to prevent oil leakage/ spray. The smaller o-ring beneath the head of the bolt seems to be doing just fine. Of course, it's hard to tell if that thing is leaking with the main o-ring projectile vomiting oil everywhere. I can conduct a pressure test to see what kind of oil pressure I'm registering. I'm not entirely certain where to take the reading from, though. Since the pressure at the filter is where the problem is occurring, I'd like to know what I'm reading in there. Any suggestions on how to go about doing that? This is terribly frustrating. Of all the things I had planned to keep an eye on and work on to keep the mini from experiencing failure, a simple oil filter housing wasn't on my radar. And now this thing has crippled my baby.

[jockduck]

Hi again, there is a small hex plug on the filter head which is where the system oil pressure is checked, you need a gauge of at least 150 psi capacity, oil press should be 75-85 psi in any gear position other than "R", in "R" it should be 115-125 psi engine warm and approx. 1000 rpm. any pressure significantly higher is not right.
No way should you be able to rotate the filter bowl when the bolt is tight, sounds like the bolt is becoming thread bound before pushing the bowl into the top seal.
Jock

[Thegurgan]

Thanks Jock. I had to wait until today to take everything apart again. I'm preparing to begin the work now. Once thing I noticed is that the dome end of the cup where the bolt enters is crushed in a bit from where my mechanic reinstalled it. It appears as though I will need to reshape it and reinforce it with a washer formed to match the curvature of the dome. Then I should be able to get sufficient pressure against the seal. I'll take some pictures during this disassembly and repair to post here. Wish me luck. Parts for these things aren't easy to come by here in Washington.

[Thegurgan]

Also, are you sure about those pressures? I know the mini isn't "most cars", but I've not encountered pressures that high in any other car.

[Thegurgan]

None of the gauges I can find locally exceed 100psi. One thing I thought of was a possible stuck oil pressure relief, but I pulled it out and cleaned it and its location in the block and found nothing to suggest that was the problem. I've reassembled everything again after rounding out the filter cup where the bolt goes through, and tightened everything even more than any previous install. Now the car starts and idles with no issues, but as a test, I placed it in reverse and increased the revs a bit. Once again, I get oil foaming around the seal at the filter head.

Could the bypass tube from the gearbox to the engine block be clogged?

I'm stumped. I have never heard of a mechanical oil pump suddenly pumping extreme pressures, and I find it hard to accept that the torque I have on the filter cup bolt isn't sufficient to apply enough pressure against the filter seal...it now has more pressure than the car has ever had before. 

This issue has my car crippled. I can't move it, and I'm extremely frustrated at this point. This is something that happened suddenly without any warning, leading me to believe something has broken or clogged. I've already changed the filter and seals, I'm using the thicker seal, I've checked the oil pressure relief valve, and I'm 100% certain that the filter and seal are installed correctly. 

What am I forgetting or missing here guys?

[richard1]

Glade to see I'm not alone. What I'm taking away from this is that I will check to see whether my bolt is bottoming out before putting enough pressure on the gasket.

Going back in time: When I assembled mine, I had this problem. But I also had a smashed disc in my transmission. That is fixed, but I still had the problem. In the process of diagnosing the transmission, I ran the above mentioned pressure checks. Had to go to several stores to find a gauge high enough. Where I got it caters more to the diesel truck crowd.
This is measures, as noted, at extra bolt/hex nut at the filter housing. You can see that the pressures are what are recommended in the earlier post.

Forward pressure.


Reverse pressure



I tried the various gaskets that came with my filters, but none wanted to seal in that funny little V groove in the filter head. Checking the specs of the gaskets that come with different brands of filters, I saw that no two brands were alike, with variances from 1 mm to 6 mm. My gaskets kept working their way out. So I took the filter head to the lathe and opened up the space to hold a real gasket, purchased at the local gasket/o-ring store, later shown to be the one that comes in the Donaldson filter box.


If memory serves me, although it seemed like a lot, I put the recommended 15 ft lbs of torque on the filter. Wonderful! No leaks. After a few other things, I had it ready and drove it to town for an alignment (25 km). No problems. As I got home that night, my oil pressure gauge started going crazy (a sure sign of air getting into the system from low oil). After I drove into the garage, I noticed a trail of oil. But a plane trip the next morning, so had to put off diagnosis.

On my return I found that the leak is at the filter again. This is a frustration and a relief (wouldn't want it to be somewhere that required pulling the engine again). But for reasons I can't control, had to fly back out. Going back next week, so I will check some extra washers on the bolt, but still question the bypass.

I have questioned the relief valve (to myself), and maybe Martin will chime in on whether that could be weakened a little without hurting other pressure needed. I'm running 10W-40 Motorcycle 10W-40, with about 90 psi on startup and 40-45 psi once it warms up.

[Thegurgan]

I took everything apart again, and I decided to see how much pressure I was actually getting against the seal. I took the filter and spring out of the cup and just put it against the o-ring. When I put the bolt in and ran it as far as my fingers would take it, I was left with a gap between the bolt head and the washers!! I'm blown away here. I put the thicker o-ring in and added two washers when all this began. I even used a hammer and a dowel to flatten out the area where the small washer fits by the bolt head. How did this thing EVER have enough pressure against the seal before?!? I'm going over to the hardware store in a bit to get another washer or two. I'll report if that fixes it once I get everything reassembled.

[limby2000]

Sometimes the obvious seems too simple, fingers crossed.

[jockduck]

Hi again, I checked out my spare 'box today, the centre bolt will screw in at least 3/4" more than required to pull the filter up. I find it hard to see how the bottom end of the bowl could cave in, I tried turning the bowl and found it impossible after I tightened the bolt up finger tight! The bowl fits inside the head approx 5/16" I can't understand how the seal gets squeezed out.
Jock

[Thegurgan]

I am once again stuck with the same problem. There is absolutely no way that the amount of pressure I have against the o-ring isn't sufficient to handle the stock oil pressure. Here is what I've done so far:

-It began by placing the car in reverse. I heard a spraying sound, and lost rearward propulsion.
-Upon inspection, the o-ring for the oil filter had squeezed out from under the bowl. At the time, I was using the thin o-ring.
-I disassembled everything, re-seated the o-ring, and reassembled. Placed the car in reverse and got the same result.
-Disassembled everything, and seated the larger o-ring in place. This time, it didn't spit the o-ring out, but sprayed oil from around it.
-I now added two washers under the bolt to add pressure to the o-ring. Same result in reverse.
-I disassembled and inspected everything.I found no blockages in the filter head. I checked the oil pressure relief valve. Reassembled. Same result.
-I disassembled and checked the filter head/ bowl assembly without the filter in it. Found the bowl needed more washers and added them. Reassembled. Same result.

I'm now sourcing a pressure gauge to test the oil pressure. I still can't understand how a mechanical oil pump could suddenly start pumping excess pressure. Conducting this test feels like a waste of time. But, I can't understand anything else that's happening here, so why not? 

Does anyone else have any suggestions as to what is going on here? Any ideas on what could cause the oil pressure to increase? I haven't determined that is my problem yet, but while I wait for the pressure gauge, I'd be curious to know what could cause an increase in pressure, aside from the oil pressure relief valve being stuck.

[Stu]

Have you checked to see whether the oil pressure relief valve is not sticking?

[Thegurgan]

Here are the photos of the housing without the filter installed from my earlier post.   
You can see the space under the bolt head that I was talking about. The o-ring is in place and is the thicker of the two options. The bolt is as tight as my fingers would get it. I ended up adding 4 washers under the bolt head, and that still wasn't enough to make it seal under load. I've ordered a pressure gauge that will register up to 300psi, just to be certain that I can read whatever the real pressure is at the filter. It should arrive by this weekend. And to answer the last question asked in this thread...yes. I checked the oil pressure relief valve. I removed the cover, the spring, and the bullet-shaped plunger and checked to see if there was anything causing it to stick. I couldn't find anything that would prevent it from proper function.

[jockduck]

Hi again, the end of that bowl does look caved in and the thick washer thing does not look like the ones on my filters.
Jock

[jockduck]

A photo of the filter on "OTTO" , I should be able to add more photos in a day or so.
Jock

[kalkat]

Yup, that looks like crushed/collapsed bowl syndrome...............

The end of the filter bowl is somewhat thinner than the rest. Once the sealing area starts to deform (very common) the rest happens easily



Emma

[Thegurgan]

So I understand that the end looks (and most likely IS) crushed. But I've added enough washers to overcome any deformity there. And unless it continues to flex under the pressure of the oil in the cannister, I should be sealing against the o-ring at the housing. The bolt end isn't where my leak is coming from. I should have my oil pressure gauge tomorrow and then I'll know more.

[jockduck]

OK did an oil and filter change on "OTTO" today, the Mahle filter came with 3 seal rings one was very thick and obviously did not fit, I used the middle sized one, the smallest one probably would have worked too, I wish the filter makers would include the "O" ring for the other end, the one I am using is many years and filter changes old. any way some more photos.


Jock

[wimfournier]

I wonder; the thread end in the filter head, is it deep enough for the bolt to have a few mm left when it is screwed into the bitter end?
The bolt that we are talking about is turned into a threaded hole in the filterhead. When the hole is not deep enough respectively, when the bolt is too long to press the filterbowl enough against the filterhead, the bowl will not sit tight enough to keep the rubber ring in the groove under the high oilpressure when you choose reverse.

[Thegurgan]

Wow. OK. Mine is pretty damaged. I'm going to attempt to repair mine and reinforce the bolt end with something. I'm also going to test the oil pressure. I'll report back once i have some results. Thank you all for the help so far.

[Thegurgan]

OK. I have some pressure results.  I didn't allow the car to run up to warm operating temperatures, mostly because I didn't want it running for long while fighting to keep oil in it. With it cold, and with 20W-50 mineral oil in it, at idle I have a steady 100 psi. When reverse is selected, it remains at 100 psi until I add throttle up to roughly 1000rpm, and then it jumps to 200 psi momentarily before settling back to a steady 150 psi. 

We've concluded that the cup is damaged., and I will have to call upon my metal shaping skills to try to return it to a serviceable shape again. 

But do you guys think those readings are within limits? I know Jock said 75 psi at idle and 125 psi in reverse. I assume those were "warm" pressures and mine are "cold" pressures, which should account for the 25 psi variance. Is you're experienced opinion that I simply have a damaged and failing cup?

[wimfournier]

Aha! You should use 10W40.