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MG Midget and Sprite Technical - and now for the bad news - new project

One problem was bad enough but then it went from bad to worse. ;)

I was getting my 73 ready for a little testing at the autocross track, I topped up the fluids and all that stuff and packed up my road kit and left friday night to drive 40 minutes to my house where the car would be closer to autocross where I had to arrive by 7:00 AM.

It was starting to get dark. I was driving along a 4 line divided highway with 18 wheeler trucks barreling along (a little scary in a midget I have decided). Anyway, you get the picture. I started to smell some oil burning. It smelled like it was getting on the manifold. I suddenly got the idea that I might have forgotten to put the valve cover cap on. I pulled over (way over in to the grass to beyond the brakedown lane) and shut down the engine. I lifted the bonnet and could even see a little slight smoke from burning oil. The valve cap was on. Darn. This means that something else is wrong. The oil pressure was 65-70 (fine) and the engine was running cool (as it usually does).
HOWEVER..... There was oil all over the place on the front lower and left lower sides of the engine area. A big mess. I could not see where it was leaking. Luckily I had a large rag with me. I wiped it up as well as I could in dim light on the side of the highway. I checked the oil level. It was a little over full. Darn. I now suspected that I over filled the oil and that it blew out the front seal and timing chain cover.

After looking at the markings on the dipstick, in retrospect I think that I filled it at least 1/2-1/3 qt over. For an engine this size that is a lot I think. I am so used to driving vehicles that have more than one qt from min to max on the dipstick that I was not thinking (my buick has an 8 qt capacity for instance). I only added 1/2 qt when I was servicing the car prior to leaving.

I should say, that before this happened, there was not a drop of oil leaking from my engine.

I got back on the highway and drove two more exits (not very far). I stopped at a gas station and popped the bonnet. Darn. Again, there was oil all over the front and left side of the lower parts of the engine area (including burning on the exhaust flange). All of the oil was on the front cross member or front of the engine, or on the left side (as seen by the driver) below the heat shield including all over the fender area and steering column. I wiped it up and did a better job this time. Then I drove home (20 minutes from there on a back road).

When I got home there was not that much oil. I started to think that my theory of over filling the oil was correct because it seemed to be leaking less and the level was almost down to normal maximum. I wiped up the oil and decide that the car would be dry tomorrow and that I can do the autocross race.

The next day I drove on back roads (25 minutes) to a gas station near the track. I smelled burning oil on the way (not a good sign). I popped the bonnet. Argh. Oil all over the place, as bad as ever, and it was dripping out the bottom of the car. I wiped it up and started to decide that I cannot race. I drove down the road to the track and parked. hm, not much oil. I decided to try racing but wiping it after each run. I tried that for two runs but I got tired of burning my knuckles so I packed it in.

Then I got a brilliant idea. I checked the oil. It was about exactly full. Why not drain out 1/2 quart and see if it stops leaking. I did that and got ready to start the engine. the bonnet was still up.
I turned the key. Almost immediately there was people yelling, "shut it off", "fire".....
I jumped out of the car with my fire extinguisher and turned off the battery switch and ran around to the other side of the car. Two other people arrived with fire extinguishers. One person blew on it and the fire was just about out (not necessary to use extinguisher).
The fire was my wiring harness high current wires. Totally vaporized in seconds. I think that it was caused by a mysterious wire that was tie wrapped back (I never knew what it was) but the terminal had never been taped up. the tie wrap broke and the wire touched one of my brake lines. Apparently this was a hot wire.

The other possibility is that the plastic backshell on the connector that plugs into my alternator which was falling apart (only just happened) permitting those wires to start wiggling too much.

Now I need to replace some or all of my wiring harness.

Questions:

Do people think that I caused this oil problem by overfilling the sump. Did I damage the front seal? Is it possible that the oil level is not too high now but the timing chain cover is full of oil and is still leaking until it is gone (I would have expected that it has a way to drain back though). In other words, is it possible that this leak will just stop when the oil in places where it does not belong is out or do I have a big problem. Do you think that I need to remove replace the front seal, timing chain cover gasket and oil pan gasket?

My valve cover hose was removed by the way:
http://www.pangalacticconsortium.com/cars/MG_Midget//imgpages/image276.html

You can see that it is missing in this picture. I forgot to put it back. I have a vented oil filler cap and a hose that just goes down to the back of the firewall (no smog system). If I had a blowby problem oil would have been coming out of that fitting so I don't think that this is the cause of my problem.

I also checked the hose coming from the air oil separator at the carb ends. The hoses were dry.

I can't think of any where that this oil can be coming from other than from under the timing chain cover.
Apparently my engine does not have tappet covers. I checked for that.

so, who makes the highest quality replacement wiring harness?

Rebecca
R Harvey

my personal opinion is your fine on the oil seal, those things fit super tight as is, and it sounds like you blew out the excess oil is a short period of time

try re-torqueing the head, a long time back I had a mystory oil leak in the same location ...somehow the head got loose in that side corner (usa drivers side front) and it was shooting oil everywhere....theres an oil passage thats hard to seal in that corner

as a long shot there is a brass pin hidden under the front of the head that can loosen and leak...its hard to see and find, but its rare that little pin leaks

try

http://britishwiring.com/

for a wiring harness

In your other post, it didnt look like your valves where opening vary far, I wonder if the camshaft is worn
Prop

Rebecca,
You do have a very nice clean car and clean engine which should make it much easier to track down the source of the leak. For oil to be spreading at the very front of the engine does suggest either the timing cover or front crank seal or maybe the oil feed gallery in the head that Prop mentions.

But as it is low down on the engine you could check that the sump bolts are still all tight in that area. I also see that your engine has the blanking plate for the mechanical fuel pump lower left of the block beneath the carbs. - check that that hasn't come loose.

I think the fire is just a bad-luck coincidence. But maybe the wire was dislodged when you were wiping up the leaking oil with a rag in the dark. That might have been the bad luck bit!

I like your car - very nicely prepared!

Guy
Guy Weller

Is that your garage?!!!
Gary lazarus

yes that is my garage. I checked the blanking plate and it is not the source of the leak. it seems to be coming from the lower front.

regarding the wire coninsidence. I am not sure it was due to the wiping because the leaking was the other side of the engine but I did do some inspection on that side so you could be right.

I will post some pictures of what my wires look like after I unwrap everything.

Rebecca
R Harvey

heck with the car...I love the plane...now thats a cool garage...I assume your drive way is a runway.

Prop
Prop

My "Garage" is actually an airplane "T" hangar condo. I own this unit (part of a six unit building). It is at an airport using airport transfers sevenoaks. I have no garage where I live. The monthly condo fee is very reasonable considering that I make maximum use of it (most people just have one plane in their hangar). My plane is so small that cars fit with it.

Rebecca
R Harvey

"Do people think that I caused this oil problem by overfilling the sump."
>>No, a half qt or even a full qt won't cause a problem. No seals or gaskets are under pressure, which won't increase with a bit of extra oil anyhow. Problems arise when the crank starts thrashing around in the oil, which takes a lot. Then the problem is foam causing low oil pressure and heat.

Did I damage the front seal?
>> No, but it sounds very likely that the seal has simply failed. Lip type seals do this if the lip wears through. I seem to recall that this car had sat? This frequently results in rust forming right at the seal lip contact, which then eats the seal after short use.

Is it possible that the oil level is not too high now but the timing chain cover is full of oil and is still leaking until it is gone (I would have expected that it has a way to drain back though).
>> No, lots of drain capacity there.

In other words, is it possible that this leak will just stop when the oil in places where it does not belong is out or do I have a big problem. Do you think that I need to remove replace the front seal, timing chain cover gasket and oil pan gasket?
>> Not a really BIG problem, but a day's work to R&R rad and etc. Most likely you will need to replace the seal and cover gasket; sump gasket is not affected. And the timing chain is undoubtedly quite worn if the car has had typical use - mileage?? Worn chain causes late valve timing, which costs power and fuel and frequently oil consumption; if this is the case, you will be very glad after you replace the chain and time the cam in right. I've seen 10-15% improvement in all of these just from replacing the chain and setting the cam up right, even on very worn engines that really need a rebuild.

My valve cover hose was removed by the way:
http://www.pangalacticconsortium.com/cars/MG_Midget//imgpages/image276.html

You can see that it is missing in this picture. I forgot to put it back. I have a vented oil filler cap and a hose that just goes down to the back of the firewall (no smog system). If I had a blowby problem oil would have been coming out of that fitting so I don't think that this is the cause of my problem.

I also checked the hose coming from the air oil separator at the carb ends. The hoses were dry.
>> You are correct on blowby - good. If you have a vented cap AND the valve cover hose open, then you are pulling too much air into the carbs via the breather lines. The carb needles are calibrated to account for the amount of air that would pass through the little hole in the VC elbow, more is a problem. This means you have to set the carbs rich to compensate at idle, but they are then too rich above idle. Either fit a non vented cap and a filter on the VC elbow, or block the elbow and restrict the vent in the cap to the same size as the calibrated hole in the elbow. The bottom plastic disc in the cap will snap out and a restrictive piece can be put inside it.

I can't think of any where that this oil can be coming from other than from under the timing chain cover.
Apparently my engine does not have tappet covers. I checked for that."
>> You are probably correct, though there are numerous arcane and rare leak points such as the one Prop mentioned. LH front corner of the head is sometimes a problem, but your description sounds like TC seal. You have the thing so clean and the leak is so great that it should not be hard to get it warm and see where the leak is.

>>PS Image 282 etc. Grab the elbow coming out the top of the manifold with a pair of Channellocks, and twist/pull - it will come out. Plug the hole with a neat 1/2" dia x 1/2" long aluminum plug with a bit of sealant on it. This will improve the look of things no end.

What color was the suspect wire? More after you show & tell.

FRM
Fletcher R Millmore

Fletcher - that is what I would call a useful response - logical, systematic and practical. Good one!
Guy Weller

Fletcher, thanks for your excellent comments.

If I recall the offending wire was coffee colored (with cream). ;) I should take a look again before further discussion about that.

Regarding replacing the front seal (and timing chain):

The book says that removal of the radiator is required. That makes sense. However, I cannot see how to get the bolt that holds on the harmonic balancer and pulley off without raising the engine so that the front of it is more above the front cross member. I don't own any tool that can fit on that nut. There does not appear to be clearance. Also, do I need to be able to position a puller onto the front of the balancer?

I have never changed a timing chain before. It seems straight forward but I might need some tips. Usually I order parts before taking the car apart. However, this time I am going to take things apart this weekend and then order my parts on monday. I need to get the car back on the road before the end of the month though.

Another thing, I need to replace the shocks (too squishy and one of them is bad). This should be a different thread though.

Thanks,
Rebecca
R Harvey

Rebecca,
You release the front engine mounts and raise the front of the engine, maybe a 1 1/2", just enough to get at the front bolt and pulley(harmonic balancer). The nut can be very tight so you will probably need to put the car in 1st gear and have someone press firmly on the brakes, whilst you use a good socket and breaker bar. Sometimes an air impact wrench is very effective.

Once the nut is off the pulley should come off quite easily - it is keyed onto the shaft.

When replacing the timing cover with a new seal and gasket installed, put the bolts into the block in loosely at first put the pulley on and then rotate the engine a couple of times. This centres the new seal properly before you tighten the timing cover bolts. If you don't do this the new seal can wear very quickly!

When renewing the timing chain, consider using a duplex one if it doesn't have one already. They are less prone to stretching.

Guy
Guy Weller

Shocks are simple call Peter (800) 362-1025. He can install uprated valves in a rebuilt pair (if that is what you want). He stands behind his work.
Trevor Jessie

I don't have an engine hoist (but I could find one to borrow if it is necessary). Is it possible to just put a piece of wood somewhere under the engine and jack it up a little with a floor jack or would that cause damage. I have done that with heavier more robust engines and did no damage (oil pan in that case).

If I used an engine hoist, where would I connect it? I don't remember off the top of my head if my engine has a hook on it. I have never removed an MG engine before so I never had to think about this.

Thanks,
Rebecca
R Harvey

Yes, you can use a block of wood and jack under the oil pan (aka sump)
Trevor Jessie

Yep, just jack it on the sump with a good piece of wood to spread the load. I certainly wouldn't normally jack a car up on the sump but in this case you are only tilting the front of the engine up a bit - so long as you release the front engine mounting brackets first!.

Also it is easier to re-connect if you release the bracket from the chassis on one side, and the rubber mount from the engine on the other side.

Guy
Guy Weller

on the pulley

there is a lock tab under the bolt, you will see the tab folded over one edge of the bolt head, you will need to use a small screw driver to pry it back

Harbor feight has electric inpact wrenches cheap 30-50 dollars, buy one you will find many uses for it, yes you can loosen the bolt without an impact wrench, but its a total suck job to do it....the impact wrench is like 15 seconds andthe only difficulty is squesing the triggger...Okay fine, yes you have to plug the power cord into the wall socket also

BTW the bolt head size is (1 5/16 inch) you can rent at autozone, but id buy one as its a common tool thats needed more times then Id like to admit

when loosening the engine mounts I remove the bolts on the monuts to chassis on the USA driver side then remove on the other side the 2 nuts from engine plate to mount and loosen the single nut as much as possiable on the on the rubber cushion,,,that way the engine comes straight up with little effort

to pull the pulley Ive always needed a 3 jaw puller to get the pulley off, on the timing chain sprockets, I use a small 2 jaw puller as a 3 jaw wont fit the sprokets, If the chain and sprokets are worn aka trash and need replacing...I always use a 4 inch angle grinder and cut the chain off, much easier so finish removing the sprokets...just use a rag to cover the hole in the front of the block so nothing get in there and watch where your grinding

the (coffee and cream wire) Im guessing thats brown and yellow colored...If its a fat wire thats bad as that goes from the dyno/alt to the reg box and is the heart and soul of what powers everything...if its a skinny, then it simply light up the light bulb in the dash but it does go from the bulb to the ignition switch, so not sure how serious that is.

see page 203 in your hanyens manual
Prop

forgot to mention....I all ways remove the 2 tranny bolts on the sides of the tranny tunnel and the 2 long bolts under the car that holds the tranny in place ...I dont know if its nassiary, but safer is easier then sorry, esp for no more work then is involved.

others may have a better view then I.
Prop

As you are only going to lift the front of the engine a couple of inches at most, it really isn't necessary to disturb the tranny bolts - there is enough flexibility in the mountings there and the angle that they will move through is barely a few degrees.

It is more likely that you may have to release or loosen the exhaust pipe, unless you have a fairly slack hung system!

Guy
Guy Weller

Trevor,

I gave Peter a call and he sent me some pictures. I am really impressed. I have already made an order.
Thanks for the tip.

Rebecca
R Harvey

Thanks Guy,

ive never was clear how much give there is in the tranny mounting, so good to know. thanks for catching the exhauste pipe...I forgot about that
Prop

I will definately have to lower my exhaust. It is already too close to the underside of the body directly aft of the engine (I don't yet know what to do about that - if the engine shakes in the slightest I hear knocking).
Rebecca
R Harvey

orginally there was a clamp on the exhauste pipe that bolted to the corner of the tranny,,,you definatly want to make sure its secured and not swaying in the wind so to speak...if not it will cause all kinds of bad issues...I use straping metal ...its a stip of flexy metal with a bunch of holes in it that can be bolted


Prop

Rebecca,

Awesome hanger you have there, spent my lunch time looking through your pictures… can I ask what’s the green car lurking in the background ? at first glance it looks like a XK140 but the rear lights, then I thought a MGA – nope, then I started thinking something much rarer like Fraser Nash …

Or am I completely wrong and its some fantastic looking American car I’ve never heard of, any chance of more pixs ?

Sorry to be off topic, your midget looks great…
M Mason

The green car in the background is indeed an MGA (62). After I get the Midget more or less finished I will start on that. It is pretty well gutted now. no engine, no interior, no floor, no wiring etc.

Or were you talking about the other green car that lives above the Midget. That is a 1950 Buick Super Riviera. Here is a better picture of it:
http://www.pangalacticconsortium.com/cars/NewBuickGallery/imgpages/image023.html
http://www.pangalacticconsortium.com/cars/NewBuickGallery/imgpages/image024.html
http://www.pangalacticconsortium.com/cars/NewBuickGallery/imgpages/image017.html
the engine is a straight 8 that weighs 800 lbs.


Rebecca
R Harvey

id put a huge cig comming out of the grill, it just looks like it needs one.

But the heat vents would be perfect for the midget wings
Prop

That was the MGA with Mini style tail lights.
Trevor Jessie

This thread was discussed between 10/08/2010 and 14/08/2010

MG Midget and Sprite Technical index

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