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MGA 1500: Burning oil/compression problems (Long)

To: "MG List" <mgs@autox.team.net>
Subject: MGA 1500: Burning oil/compression problems (Long)
From: Steve Morris <smorris@en.com>
Date: Thu, 24 Aug 2000 00:30:37 -0400
Hello Listers!

I'm fairly new here, and I've only had my 1958 MGA 1500 Roadster a week 
now. As this is my first LBC, I've been one happy camper until the last 
couple of days. Now I'm kinda down, and could use some advice.

I purchased a beautiful frame off restoration, with the engine rebuilt by 
a reputable engine shop. Block was re-sleeved, new crank, pistons, cam, 
cast iron rings, hardened seats and guides (no lead additive needed), the 
works.  This is #15GD-U-H 6014 engine from early '59 with the high 
starter mount, BTW.

Yes, it burned a little oil, and puffed blue smoke on revving after a 
idling. New rings...that's to be expected. Plus it has those O-ring valve 
stem seals instead of "real" seals. The engine had about 1500 miles on it 
when I picked up the car last Tuesday.

I drove home 150 miles with no problems. Runs with 65 PSI oil pressure at 
3000 RPM cold, and about 45 PSI hot. Idles at about 20-25 PSI at a pretty 
low idle RPM. Runs at 190 degrees F without wavering until I shut it 
down, then it climbs to 212-220 as the coolant re-absorbs the engine 
heat. I topped off the oil (3/4 quart-didn't check it before leaving, so 
I don't know how much I consumed.) It didn't smoke much during the trip, 
and ran great. I drove around a bit that evening with a big ol' S*** 
Eating grin on my face.

I drove it about 25 miles Wednesday, and then not again until Sunday. 
Gorgeous day, and we ended up with 112 miles of country roads under our 
wheels. I noticed some pinging on some hills, some bogging when starting 
from idle, and more smoke than previous, but ran fine. Only problems I 
had that day was flooding when I started it (One problem with showing off 
a new car, is remembering that the starting sequence is a bit different. 
Just inserting the key before pulling the starter doesn't work. You've 
got to actually TURN the key!), and running on when I shut the engine 
off. Starting seemed to be getting harder, too.

I got home and checked the oil again. Whoa! I needed another 3/4 quart to 
get it back into the middle of the add/full range!

I drove it to work Monday (about 25 miles total), and it starting hard 
(doesn't need choke even on cool morning. In fact, even a little throttle 
almost floods it.), smoked even more, and pinged a lot more. I stopped to 
pick up a case of oil (Pennsoil SAE 30 HD), and by the time I got home, 
it was clattering on every acceleration and low RPM loading. It took a 
full quart to bring it up to full! (The dipstick is supposed to bottom 
out in the sump, isn't it?)

Tonight I checked compression (about 6-8 compression cycles) with engine 
cold: #1-150 psi, #2-75 psi, #3-75 PSI. #4-135 PSI. The PO checked them 
as all 150 +/-3 PSI after the rebuild. My first thought was a leak 
between #2 and #3, so I put the #2 plug back in and checked #3 again. 
Then switched and checked the opposite. No change. I next put about a 
tablespoon of oil and rechecked: #1-220 PSI, #2-120 PSI, #3-110 PSI, 
#4-210 PSI. All four plugs are heavily fouled with wet oil and heavy 
carbon deposits. Coolant is clear with no signs of oil contamination, so 
block integrity seems OK.

Questions: Should the cast iron rings have seated themselves in the 
almost 2000 miles since the rebuild? Should I be getting that much build 
up in only 2000 miles? Should the wet reading have increased that much on 
the apparently good cylinders? I don't know if I'm getting leak-down, 
because my gauge (a good one from K&N) has the pressure holding feature 
with the valve at each end of the hose. I'll have to see if I can get the 
hose end valve stem out. The pinging and clattering seemed like 
pre-ignition (detonation) or bad timing. I checked the dizzy for 
looseness, but no problem. I haven't timed it, because I'm a little 
afraid to start it again.

I think the next step should be to pull the head and to remove carbon 
build-up, shouldn't it? I should get the "real" seals in, as well, since 
there is apparently much too much oil getting around the valves. I'll 
probably have to get a valve job as well, since I imagine the seats are 
burned or carboned up with that much compression differential.

Two and a half quarts of oil in a little more than 300 miles is 
excessive! It must all be burning, since I don't have much dripping when 
the car is setting not running (half a dozen dime sized spots after two 
days of sitting), but after a few minutes at idle and revving, there is 
an inch and a half diameter spot, plus some other drips. I haven't 
isolated it yet, but it all seems to be coming from the bottom somewhere. 
Nothing is leaking around the head, rocker cover, timing chain cover, 
vent, or pan. It all seems concentrated at the engine/tranny joint and 
back, including the tranny drain plug, frame crossmember, and bell 
housing weep hole. This can't be crankcase overpressure can it, since 
nothing seems to be coming out the vent pipe?

I sure am disappointed! I bought a completely restored car because I 
didn't want to have to do anything major this time. I've had other 
project cars and know how long they can drag on. This time I went for the 
instant gratification. Can I start this car in this condition, and more 
important, will running it do any further damage? Does an octane booster 
help to combat pre-ignition? (seems like it would do the opposite) Am I 
going about this in the correct sequence, or am I overlooking something 
obvious?

I think I'm going to need some professional help on this one. Does anyone 
have any opinions or recommendations on Omni Specialties in Cleveland, 
Ohio or Pierre Goasdoue's Upstairs/Downstairs British Car Specialist in 
Mansfield, Ohio? Any one else in the Cleveland area I should look into? I 
talked to Pierre on the phone before I bought my car about another one, 
and he seemed a really helpful guy.

If anyone has any advice, questions, or suggestion, I sure would be 
appreciative! I'd sure rather be driving my new little red MG than have 
it in the garage with the bonnet up and smelling like the corner oil 
recycling station!

Thanks for any help that can be offered,
Steve

Steve Morris
Avon, Ohio
1958 MGA 1500
Red/Black


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