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1500 engine issues

Posted by Ohiospider1975 
Ohiospider1975 Avatar
Warren Brown
Ohio, USA   usa

I took my newly purchased MGA out for my first drive. Well sort of. The car starts, and commences fine. Engine to transmission interaction fine. But within minutes it is quickly overheat(temp gauge climing from 160 through 190 up above 212++ F). At this point the engine is unable to accelerate the car no matter how much I depress the gas pedal. No power. I have to disengage and play with the clutch to get the engine up to 3500 rpm. Once there, the engine will pull the engaged gearing up above 4500. But if the engine falls down below 2500 rpm, I cannot get it to accelerate. This is in 2nd or 3rd gear. If I take my foot off the gas, then the engine immediately stalls. It will not restart until it cools down (20 minutes). Then the process starts over again. Radiator is full, but the cap has no seal. Fan turning on belt, not loose. Lots of gas smell. When the engine is hot, lots of backfiring and load sputtering (pre-ignition?) Does not occur when starting out with cool engine. The transmission housing by my right leg puts out a lot of heat. I mean a lot...enough to make me sweat. I went on a 50 mile drive. The first 10 were fine. Then the fun began. 2nd 10 fine after a 30 minute wait. The final 20 were a drag. When the car is hot no matter how far a depress the accelerator, I barely get an idle response. Any uphill grade, kills the engine.

Any thoughts?
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TeamEvil Avatar
Kingston, Massachusetts, USA   usa

Whoa, is this a joke post?

When the engine overheats you don't WANT to accelerate or rev the engine up to 3,500 hundred rpm or do anything else other than shut it off ! ! ! !

Without a seal in the cap your cooling system is no longer pressurized, and the water will just peculate off and . . . hey, WAIT a minute . . . this IS a joke post isn't it ? ! ? ! ? ! ?

And I fell right into the trap.
Basil Adams Avatar
About 12 miles from Sears Point, CA, USA   usa

Check your timing and vacuum advance. If you have too much advance dialed in, it will overheat. Best of luck. Basil

Basil C. Adams
1956 MGA Coupe (Show Car)
1957 MGA Roadster (Driver)
1958 MGA Coupe (Racecar)
1959 MGA Coupe (unrestored)
1960 MGA Coupe (unrestored)
1960 MGA Roadster (Driver)
MKIII Elva Courier (E1056)
1967 427 Cobra
1972 Alfa Romeo Montreal
A coupla late MGBs
1960 Austin Healy BN7
More Cars than Brains
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Rowdy Avatar
Jeremy B
Brisbane, Australia   aus
1960 MG MGA 1600 "Little Red"

Check your thermostat isnt stuck closed, I had anew thermostat seize closed after approx 1500kms. Coolant boiled every time, but i didnt rev it or drive far, looked for the problem instead.
Marty R.
Hollywood,CA., USA   usa

Gee Warren... as Thomas C put it..... maybe you are joking.... in that case I'll go with it and advise draining the radiator and removing the fan belt. Drive your car uphill into a bad traffic jam. See if there is any change. If there isn't then you'll know it must be the timing. If you've gone to 12 volt thatn put the battery on the other side to draw the heat. Put the car uo on jackstands and place a brick on the accelerator pedal. Walk away for one hour... if there are still no changes than it could be the ....I 'm guessing the engine block paint.
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mgageoff Avatar
Geoff Howard
Ashburn, VA, USA   usa

Since he's probably not kidding, can anyone explain the correlation between engine temperature and clutch function? MC fluid temp?

Geoff Howard
Now Playing on the Blog (8/8/2013): Don't Blow Your Top
HL Miller Avatar
Henry Miller
Chair City, NC, USA   usa

In reply to # 1989803 by mgageoff Since he's probably not kidding, can anyone explain the correlation between engine temperature and clutch function? MC fluid temp?

It sounds like the clutch is working OK -the way I read it, he's depressing the clutch pedal to rev the engine up without a load on it, then engaging the clutch at a higher rpm where the overheating engine now has enough power to take the load without stalling.
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Ohiospider1975 Avatar
Warren Brown
Ohio, USA   usa

I am not a sadist and this is not a joke. I flew to Florida to take possession of this MGA. I had purchased it in December while it was still in a British Car Garage there. I had the wiring harness replaced and any problem other issues resolved by the same British Car Garage near Sarasota airport.

So, I wanted to drive the vehicle. My plan was to drive it, park it at my brother's condo, and then in March have someone trailor it back to Ohio. That still is my plan. But, immediately on Friday afternoon I started facing these unanticipated engine issues. I had just been told by the garage owner that the car checked out fine. I decided on Saturday I was going to drive from Sarasota over to Long Boat Key, back up along the islands to Bradenton Beach and then back down Tamiami Trail to Sarasota. Well, I konked out several places. Once in front of the Sarasota Exotic Car Show outdoor display. People thought my car was part of the display and they pushed me out of traffic to the curb. Another konk out at a two lane draw bridge that went up. I made lots of friends with the cars backed up behind me. Several waved their fingers in appreciation. Other times, I was able to swerve out of traffic to park it along the beachfront or golf course to rest and cool. I had to reposition the car for transit north next month and I was not leaving it in the garage where I was continually told everything is fine.

But, problems need to be solved. So, I asked for your input. Thanks again.
Ohiospider1975 Avatar
Warren Brown
Ohio, USA   usa

Yes, the Clutch is fine..just getting abused, that is all. As Henry understood, I was using the clutch to increase engine RPMs to get up to where I had some engine power (3500-4500 RPM). In addition, when I would restart, I noticed small gasoline drip along the front of the carberetters spindle throttle near the float chamber onto the heat shield below.
Neil MG Avatar
Neil McGurk
Cumbria, United Kingdom   gbr
1956 Morris Minor
1958 MG MGA
1960 MG MGA
1961 MG MGA
1966 Jaguar Mark 2   → more

It might not be the temperature causing the problem, although it is running too hot and that needs to be sorted out. It may be the condenser that is failing when hot, that could cause your symptoms.
Gary E Avatar
Gary Edwards
Kernersville, ,N.C., USA   usa

A bad coil will also fail when heated. You need to get the correct radiator cap also. You need a 7 lb cap with a 1 1/8" reach. The MGA radiator is deep throat-ed and a short cap will not seal resulting in boil over at 212°.

You might try emailing Barry Alexander VP of the Suncoast British Car Club and ask for shop recommendations.


If you don't think too good, don't think too much.

Edited 1 time(s). Last edit at 02/20/2012 02:40PM by Gary E.
Taylor Blair Avatar
Austin, Texas, USA   usa

Warren... Sorry I can't give you a good answer. I can on the other hand relate to a lot of what you are saying. I used to dread stop lights and the gauge I watched the most was the temp gauge.

I ended up doing several things, some if not most will tell you I wasted my time and money but I feel better with the car and it seems to behave.

1. I put a temp gauge up from the local auto parts place under the dash so I could tell what was really going on. A pegged stock gauge was really about 210.
2. I wrapped the exhaust manifold.
3. I had a machinist at work cut me two exhaust shields using the stock one as a template. I used the stock carb spacer in between the two aluminum shields. That helped the surging and lack of power.
4. I replaced the radiator. I guess I could have had my original one redone but I felt better with a new one, I got an aluminum one. People on here get into a pissin' contest about what will transfer heat better but I went with what I felt most comfortable with. Changing that really helped with the temps.

Now on a stadard day I run about 160... dead of Summer at 110 I might, might touch 190.

Hope you get it going and if you are ever out in Texas drive by and we'll wave at you with that one finger of appreciation.

Take care,
jackalley Avatar
Jeff Allen
Mass, USA   usa

Maybe a few issues non related...

I had overheating issues that needed to be sorted out (missing felt pad under the hood, missing air ducts, etc) Barny had a good list and with all those done my overheating issues went away.

I also had a lack of power once and it was due to a bad/leaking float in the front carb? Take off the top of the float chamber, shat the float, and see if the float had any gas in it...
barneymg Avatar
Barney Gaylord
Naperville, Illinois, USA   usa
1958 MG MGA "MGA With An Attitude"

A broken or loose water pump impeller will cause those symptoms, like this:

When water does not circulate it will overheat the cylinder head, and it may not even show on the temperature gauge. I once had a frozen generator the stopped rotation of the fan belt and water pump. At highway speed the temperature gauge read 190dF while the engine was losing power rather dramatically, and it was not from hot carburetors.

It turned out that a new generator pulley with integral fan the I had just installed was fouling on the belt tension bracket bolt head. After I clipped the corners off of all the fan fins to clear the bolt head, all was well again.

Barney Gaylord - 1958 MGA with an attitude -
2mgs4doors Avatar
Harry Rathvon
Lancaster, Pennsylvania, USA   usa

I've had vapor lock problems( i'm blaming ethanol in the fuel) the past several years with my MGA coupe and 20 minutes was about the same time it took to cool down enough to get it restarted. Then again something else was festering that took some time to come to a head!....Last summer it started running bad and i was assuming vapor lock again......well i couldn't get it going and had to get it towed home.....problem....bad rotor...lots of talk in the past here about a bad batch of did last for about 5 or 6 years but i don't put many miles on it.....I also had the cracked float in the TR6 that filled with gas and sunk,had me baffled for quite some time..another thing to think about these days if old gas......i was told that gas loses about 1 point of octane a month....My MGTD suffered from this a couple years ago and just didn't run gas cured that !
Blueosprey90 Avatar
Jeff Sienkiewicz
New Milford, CT, USA   usa
1959 MG MGA

Well Warren, congratulations on purchasing the new car. Sorry about your mechanical issues. The good news is that the problems will get resolved, and then you can go to the car shows for the enjoyment and without the headaches. It will just take you some time. Persevere!

I am no mechanic so take my advice with a grain of salt. I think you have multiple problems and you will need to tackle them one at a time.

Overheating: This should not have much to do with your other problems, with the possible exception of timing. I'm thinking that you may have a water pump failure - and the reason I'm thinking that is that my friend recently reported a whole host of overheating problems that were finally attributed to a water pump which had plastic circulator veins that completely separated from the water pump shaft. So everything looked good from the outside, but the car kept overheating. Assuming you have a 180 degree thermostat, your car should not run much over 200 degrees, although it may spike above 212 degrees in standing traffic. You need the the 7 lb radiator cap (as stated by Gary E) and with that your boiling point will be 233 degrees. So first, check you thermostat (maybe pull it out temproarily). If that checks out, pull off the water pump and see if that looks like it is working. If that looks OK, you may have a obstructed cooling system and I don't know what you need to do to unplug that!

Be very careful though. Don't run the car too, too hot or you will not have an engine.

Lots of gas smell. This is probably a problem with the float in the carburetor. I believe your float bowl containers should have an overflow tube that lets overflowing gasoline drain to the ground. If the tubes have broken off, there is a real danger that overflowing gasoline will fall on the hot exhaust and cause a fire. Gasoline should not be overflowing out in the normal condition. Overflowing gasoline should not be the cause of your problems, but I would check the float bowls to see that they are properly set. Barney at the MGGuru site as a good explanation. I think the Moss catalogue does as well.

If the gas is leaking from the bottom of the main jet, it may just be dried out seals. You might be able to tighten the jet nut a bit. Alternatively, if the cork seals swell up with use, the problem may go away.

Overheating and Misfiring: In theory, I think this could be a timing problem as suggested by Basil (he should know!) My best guess is that the misfiring is not directly related to the overheating. I would start by making sure the ignition wires from the distributor cap are running to the correct plugs. I think you also need to make sure you have the correct coil on the car. Your coil, I think, should have 3.5 ohms of resistance as opposed to the type with 1.5 ohms of resistance. Once you make these visual checks, I think you have to start diagnosing in a systematic manner. I probably would start by making sure my static timing was correct. But if your car starts without too much trouble, my guess is that the static timing is more or less correct.

Otherwise, the problem could be just about anywhere. Points, defective coil, defective condensor, cracked rotor or distributor cover, bad ignition wires.

A defective coil will definitely cause a misfire and sputtering, that you will notice more with the car under load at higher rpms. My coil failed. The early symptoms were that the car ran pretty well at idle but once it heated up and was under load, it started to misfire. It went from misfie to sputter to total failure in about 35 miles. Once it failed and everything cooled down, it actually allowed the car to start for a few minutes before dying again. I happened to have a spare coil and substituted parts so hit the diagnosis on the first try. You could have a bad condensor (lots of people carry a spare, as do I), but I have no experience with that.

Good luck!
MGARuss Avatar
Russ Sharples
New Jersey, USA   usa
1960 MG MGA 1600 "Bonnie"
1993 Mazda MX-5 "Bombita"

Jeff is right that you need to work through these problems one at a time. I would bank heavily on the fact that the engine runs well when cool. By this I am assuming you mean that if you start the engine up, let it idle for a minute or two to get the oil warm and everywhere, and then at that point, the engine will rev fine and when you drive the car, the car accelerates well and pulls through all the gears. Then things start to go south when the engine heats up. So first thing to fix is this overheating - assume other things like timing are ok. Get the radiator cap fixed. I believe you can verify that coolant is circulating by looking in the radiator with a flashlight while the engine is running. Do what you have to verify that the cooling system is working well (belt, fan, pump). Once you get that fixed, see whats up with the gas smell and leak - related to the overheating or other things wrong. The last place I'd go would be spark and ignition because, again, the engine runs well before it gets hot.

Oh, and carry a fire extinguisher.

Full disclosure here - I've only owned an MGA for a few months and have little service experience with them but the trouble shooting process is independent of that. The fact that the engine runs well before it overheats tells you a lot.

Worse case scenario on the overheating is what Jack Allen experienced - you have to tear the engine down to clean sludge out of the cooling passages. Check out his blog. That you might want to discuss with the shop you bought the car from.

jackalley Avatar
Jeff Allen
Mass, USA   usa

Holly cow... someone actually read my blog! be careful, its the ranting of a rookie...
TeamEvil Avatar
Kingston, Massachusetts, USA   usa

Gotta take care of that pressure cap before you do anything else, without the gasket in place, it's like running without one. Could be the root of all of your trouble. Second, look towards the water pump, thermostat, and radiator. Finally the condition of the fan and belt.

Oh, and be sure that the bit of fiber is attached to the inside of the hood where it seals to the top of the radiator, makes a difference.



Edited 1 time(s). Last edit at 02/21/2012 07:54PM by TeamEvil.
Ohiospider1975 Avatar
Warren Brown
Ohio, USA   usa

Why is this man dropping F-Bombs on me? Is this type of vulgarity accepted here? I have never met this fellow but for some reason he cannot control his dialogue regarding my MGA. His statements appear more pointed toward me than the car. I don't understand the motivation for this offensive dialogue. Is this common here?
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