This car has always had a mysterious stumble problem and dissappearing oil and coolant but seems to run fine other than that. Well I think I just found the problem. I was letting the car idle while I added coolant and then went to add oil. Pulled the cap and I hear and feel airflow out of the crank case. Not a constant flow, but a pulsing consistent with what you would expect a cylinder to push. Havn't done much searching yet but it looks like I can buy a felpro head gasket for about $40, found a felpro bolt part number but haven't seen any prices yet. Is there anything else I need or should know? I'm very capable with engine work like this but am used to GM cars so any help would be much appriciated. For now I'm off to the search button....

 

I am thinking this might be normal from the oil fill spot.

Have you done a leak down or compression test? I wouldn't start removing the head unless I was sure. Oil leaks from our R53s and disappear as it only leaks when the car is running and never drips on the driveway. And the thermostat is known to leak and it is really hard to see it.

Just suggesting some caution before you dive in.

Rich

 

I would think that if the head gasket was blown the car would run very poorly, if at all.

 

If the head gasket were blown from piston to water jacket, you would see white smoke coming out of the tail pipe. If the head gasket were blown between oil and water jackets, you would see a white cream in the oil pan/on the dipstick. If the head gasket were blown from the piston to the outside world, you should hear something similar to a leaky exhaust manifold. That can be tested by holding a long, thin length of hose from your hear to around the gasket edge.

I agree with Rich... do the leakdown and compression tests. A local shop should not charge you too much to do that. The mysterious stumble could be due to a number of things... fowled plugs, bad wires, and corroded ignition coil pack terminals (the infamous #3 plug terminal being scorched comes to mind). Don't forget a small amount of oil is lost due to going back through the PCV hose/intercooler.

 

i'll bet what you're seeing is blowbye . this is why we have breathers and pcv systems . it's normal . do a leak down test . and a combustion solution test .

 

A compression tester isnt more than $15 at Harbor Freight. What you need to do is check that all the cylinders are all within 10-15psi of each other. If all the other cylinders are 130psi and one is like 40psi, then it's likely you have a blown head gasket.

The other thing to do would be to drain the oil and see if there is any coolant in it. I agree with Herbie that this sounds more like blow-by than anything else.

 

ran fine only over heated when going up hill . it was a warped head and blown head gasket. I even ran auto cross with no loss of time on the track. no water in the oil or smoke. you will need the complete head gasket kit to replace the head. it was a very involved job which includes taking the whole front end off , super charger , alternator, radiator just about everything. I did a valve job and bigger valves (dont recomend bigger valves) and ARP head studs ( do recomend) cost me about a grand. and two weeks work. I am fairly good at car repair having rebuilt many cars over the years. it does take special tools for the timing chain removal too. I also rebuilt the super charger at the same time(new oil very important) so good luck you will need it! peter.

 

there are many different places for the head to leak also. so there is a test for carbon dioxide in the coolant thats how my car was diagnosed.

 

Im going to do a compression test to be sure. Some blow-by is normal, but not to the extent that that you should be able to feel it like you are blowing as hard as you can on your hand. I'd be extremely surprised if there is no gasket, piston, or ring issue. I'll keep the thread updated. Thanks for all the replies.

 

Okay, Update time:

Did a compression test and all cylinders will build up to 180ish or show about 60 per stroke if I hold the check valve open on the compression tester. That seems to me like there is no problem but its an aweful lot of air pumping out of the oil cap. For my sanity I let an 03 GMC Seirra sit at idle with the oil cap removed and there is not even the slightest hint of air moving around in the crank case. So I start thinking if this is regular blow-by the only way I wouldn't notice it is if the PCV system was doing a good job of sucking the air out. I pulled one vac line off the valve cover, the car stumbles and there is lots of vacuum on it. I pull the other one (the one that goes in to the intake tube) and there is not really anything going on with it. I guess it probably won't do much at idle tho since its vac source is before the TB. So I dunno what to think now. Any ideas?

http://s264.photobucket.com/albums/i...5-18-25-55.flv

video showing me placing a rag over the oil fill location. It doesn't really sound like a tractor in person thats just the cell phone video camera doing its magic.

 

Maybe you are lucky...and have a sticky bypass valve...(might be due impart to low vacume dependind on how it is plumbed ((there are 2 similar mods to increase the vac to the bypass valve))).
The disappearing coolant....3 simple chances...coolant expansion tank (the seams often get pin hole leaks), a leaky gasket on the thermostat (also common), or a weaping weep hole on the waterpump.
For oil that is disappearing...depending on the oil consumption, it could be "normal consumption" if no leaks are noted, the oil is not showing up in the coolant. Some mini's do drink a bit of oil due to high oil temps, wear, and/or machineing. Depending on the oil brand/condition, a different one may help.
I would test the coolant and oil for contamnation before doing a head gasket...and check the simple stuff first....much faster, and cheaper that way!!

 

For blow-by....check the PCV...I have quite a bit on my '05, and have had several cars with lots of blowby...with healthy motors...sticky rings perhaps....maybe a few rotated lined up allowing blowby? Who knows...I have been told that on a motor built to be a have a blower attatched, the piston rig fitting/sizing guidlines are a bit different....so you may see more blowby than you are used to in a normaly asperated motor (I did not see you list it, but I am assuming it is a r53).

 

Sorry I failed to mention this is an n/a 02 so no blower or turbo. I'm going to look in to the pcv some more. Btw I ripped out that god aweful intake silencer and wow it sounds cool as hell! Btw 3 plugs were literally finger tight in this thing but fixing that didn't really change things. I did find what appears to be either a very minor coolant leak or maybe a/c condensation in the passenger side plastic cover that's under the radiator and a/c compressor. My wife says she did not run the a/c today so I have to think coolant but nothing ever really shows up on my garage floor.

 

Well, I'm glad we're comparing apples to apples.

I agree with checking the PCV valve.

What is the rest of the vital information on the car? Miles, etc.?

You say it's running poorly...how? Is there a CEL? When was the last time some tune-up-ish type maintenance occurred on the car, and what was replaced?

 

apples to apples of course . If someone wouldn't mind on here checking their oil fill for airflow it would be much appreciated!


It doesn't run poorly really, it just has a bad stumble right after startup and at idle like when you pull up to a stop light. As the RPMs come down they act like they aren't going to stop, then it stumbles you hear the tensioner reacting and with an old tensioner and belt it would squeal like hell when this happened. No CEL and it seems to make good power but my DD is a 500hp 98 Camaro SS so its hard to say.

Car has 80k miles, fuel economy seems good, tested before on the highway at mid 30s. Oil looks good but it definitely uses some, probably a quart low after 3k miles. Definitely also uses coolant. No leaks of any kind really other than a tiny bit of what appears to just be condensation from the a/c compressor. I have a coated garage floor that I haven't cleaned for a month and its got 2 drops of water under where the mini goes. Plugs look good (NGK Iridium), air filter is cheapo but clean. One thing I have always noticed is that the interior vents don't seem to work the greatest or make sense. Like they don't open and close properly as you turn the dial. To me thin indicated a vac leak but I can't locate one anywhere. I might try checking how much vacuum the engine is making. It was in for a tune up about 4k miles ago. Gets city driving mostly, probably 10 miles a day average.

 

An issue on my wife's Mini (2003), which I was trying to track down and couldn't till it melted a valve, was a bad intake manifold gasket. It would stumble on startup much like yours, eventually it threw a CEL. I thought it was tune-up stuff, so I did one. It helped some, but didn't fix anything. Replaced some sensors which helped some more, but didn't fix it.

I'm not sure if there's some kind of trick or test you can run, without removing the manifold, to tell if it's bad. I've heard of people spraying WD40 to check for vac leaks, when sucked into the motor, it will cause the RPMs to drop....I've never done it though, so don't quote me.

But when our manifold was removed, the gasket was completely toast. It just came off in chunks. So it was letting in all kinds of unmetered air and causing the motor to run lean.

It never crossed my mind that this could have been an issue, but lesson learned for me. Don't even get me started on the plastic pieces that they're using using inside the head.

 

Yeah, I don't necessarily agree on using composites in engine parts. However, the aftermarket Fast composite intake for LS1 SS Camaros is supposed to be a really good design.

 

That's different though, that's an intake, which using composites for is a great idea! I'm talking about plastic parts inside the head, where it has huge temperature swings from when the engine is on and hot to when it's off and cold. Not to mention the fact that these plastic peices are bathed in oil. It's just mind boggling to me that they thought this was a good idea.

Any update on your issue, animuL?

 

no update yet the car runs fine and my camaro decided to spin a rod bearing so priorities are there right now. Next plan on the mini is to check PCV system to make sure it is extracting air properly from the crank case. For the stumble I wonder IAC?

 

Have you sea-Foamed the motor yet? Many MINI owners swear by the stuff...It would clean it up...and maybe clean the sensors too....many MINI's seem to have a bit of a stumble...some yo-yo...various software updates have been made to the computers to try to fix it. I do not know a lot about "Just-a-coopers", but in general, beyond the SC, the motors are very similar...though not the same, so I think they have most of the same issues/strengths/weaknesses.

 

So, I have a problem. I recently did a "very soft" rebuild on my R52. I was seeming running too lean due, likely, to excessive boost (2% crank pulley and 16% supercharger pulley). Hence things got hot and I blew a hole in #4 piston at extended high speed. As the car is my daily driver I wanted to tear things down and inspect before removing the entire engine. I pulled the front end, head, oil pan, etc and was surprised to see almost no marring on the cylinder wall. The head had a bit of "bead blast" look and my cam was worn way beyond tolerance. So, I bought a reman head from a reputable guy. I honed the cylinders, installed forged pistons, new rod bearings, ARP head bolts, head gasket kit, timing chain kit. Got everything back together, tested compression, all seemed well. So here comes the problem. I started overheating fairly quickly. Then I found the telltale signs of of head gasket issues. Water in the oil, oil in the water, loss of coolant, abundance of oil in the pan. So, I tore it back down. The gasket seemed OK. The block seemed OK. I used a straightedge and feeler gauges to check the head, no problems. So, I ordered another head gasket, torqued everything to spec and reassembled the top end. Slight improvement....but still losing coolant to the oil and vise versa. Albeit, MUCH less and no overheating. I have retested compression, which is good, and have no leaks under the car (oil, coolant or otherwise). I had no previous issues like this so the chance that a oil cooler or something coincidentally went bad at the same time is slim. I cleaned the block very well and had minimal pitting between the coolant and oil galleries. At this point I am looking at a reman engine but, as you all know, $$$$! And, yes, I know some will say the obvious. I should have done that to begin with. But does anyone have a clue??? Could possibly save me thousands of dollars. I love my car and plan to keep it either way. Thanks in advance, Ian.