2011 transit connect idles terribly an stalls immidiately when i accelerate
Senior Member
Joined: Feb 2024
Posts: 1,191
From: California
Let me further explain a bit more deeply on possible root causes:
1) Coolant loss
The level should be checked biweekly. If there is a sign of coolant loss it can be external or internal leak or evaporated naturally especially during summer time.
Run a coolant pressure test and check for possible external leak (including the radiator cap) and if there is none, then it's likely an internal leak and result in a blown head gasket.
A blown head gasket can cause coolant intrusion (internal leak), depends on the spot, can cause coolant to enter the combustion chamber only, or into the your engine (oil passages) only, or both.
When coolant leaks into your oil passages, you can tell visually by checking your dipstick and see if anything milky like is present.
When coolant leaks into your combustion chamber, check for white smoke from the tailpipe and sweet smell.
That's why it's also a good idea to do a coolant flush regularly. And when you are experiencing just a minor coolant intrusion into combustion chamber, you MUST fix immediately or trash your vehicle.
2) A cracked cylinder head
Same symptoms as a blown head gasket shown on (1) and can also lead to a blown head gasket as the cause
3) A clogged PCV valve
Your crankcase needs to breath and thru the pcv valve (and hoses of course), when it's under high pressure and it can't breath, the vapor will need to find a way to escape, usually the weakest seals.
For example, valve cover gasket, followed by piston rings and valve stem seals, and that's how the engine oil finds a path to enter the combustion chamber, and result in so-called burning oil.
PCV valve is only a few dollar, and it shouldn't be difficult to change, perhaps your grandma can do it in 30 seconds to 5 minutes, so there is no excuse to not inspect or change it regularly.
If adding a catch can is legal in your state, just do it, especially when your vehicle uses direct injection rather than port injection. Say you live in California like me, it's not illegal but you won't pass a visual smog check unless....
4) Motor oil loss
Like coolant, the level should be checked regularly, doesn't matter if your vehicle uses electronic oil monitoring without a dipstick.
If you are experiencing motor oil loss but there is no external leak, then your motor oil finds its path into your combustion chamber, and your car is burning oil, result in blue/gray smoke.
Almost all cars older than 10 years are burning oil in some sort because piston rings are a wear part, so as valve stem seals. If you lose 1/2 quart per 5000 miles due to internal leak that's considered minor and just don't do this costly fix.
5) Driving habit
If you take short trips most of the time, do a bit more warm up at cold start (even during summer). Your vehicle needs to be in operating temperature, usually 10 minutes drive.
Let say the book tells you to change oil every 7k miles, when you do long trips the most, you can stick with 7k interval. You do stop-n-go short trips all the time, you change at 5k interval.
When your cat converter never reaches its operating temperature you have more contamination, more buildups and leftovers.
6) Normal wear
If your mom or your wife loves to throw all kind of food wastes into your garbage disposal, the lifespan can be shortened from 10 years to 2 years.
Cat converter should be made to last the life of your vehicle. If you are the 1st and sole owner of your vehicle and your cat is failing prematurely, that indicates you are not doing maintenance regularly.
Why all these matter just because ideally on a cleaned old vehicle, only air and fuel enter into your combustion chamber and you take only short trips you will have more carbon buildups alone.
When your combustion chamber has do deal with air + fuel + motor oil (because your car is burning oil shown at (4) above), more than just carbon buildups.
If it's facing all 4 (air + fuel + motor oil + coolant), your new cat probably can't handle those and definitely will have premature failure. That's also why I mentioned numerous times that you are urged to deep clean your combustion chamber using berryman 2611 after addressing the root causes and before replacing your cat.
1) Coolant loss
The level should be checked biweekly. If there is a sign of coolant loss it can be external or internal leak or evaporated naturally especially during summer time.
Run a coolant pressure test and check for possible external leak (including the radiator cap) and if there is none, then it's likely an internal leak and result in a blown head gasket.
A blown head gasket can cause coolant intrusion (internal leak), depends on the spot, can cause coolant to enter the combustion chamber only, or into the your engine (oil passages) only, or both.
When coolant leaks into your oil passages, you can tell visually by checking your dipstick and see if anything milky like is present.
When coolant leaks into your combustion chamber, check for white smoke from the tailpipe and sweet smell.
That's why it's also a good idea to do a coolant flush regularly. And when you are experiencing just a minor coolant intrusion into combustion chamber, you MUST fix immediately or trash your vehicle.
2) A cracked cylinder head
Same symptoms as a blown head gasket shown on (1) and can also lead to a blown head gasket as the cause
3) A clogged PCV valve
Your crankcase needs to breath and thru the pcv valve (and hoses of course), when it's under high pressure and it can't breath, the vapor will need to find a way to escape, usually the weakest seals.
For example, valve cover gasket, followed by piston rings and valve stem seals, and that's how the engine oil finds a path to enter the combustion chamber, and result in so-called burning oil.
PCV valve is only a few dollar, and it shouldn't be difficult to change, perhaps your grandma can do it in 30 seconds to 5 minutes, so there is no excuse to not inspect or change it regularly.
If adding a catch can is legal in your state, just do it, especially when your vehicle uses direct injection rather than port injection. Say you live in California like me, it's not illegal but you won't pass a visual smog check unless....
4) Motor oil loss
Like coolant, the level should be checked regularly, doesn't matter if your vehicle uses electronic oil monitoring without a dipstick.
If you are experiencing motor oil loss but there is no external leak, then your motor oil finds its path into your combustion chamber, and your car is burning oil, result in blue/gray smoke.
Almost all cars older than 10 years are burning oil in some sort because piston rings are a wear part, so as valve stem seals. If you lose 1/2 quart per 5000 miles due to internal leak that's considered minor and just don't do this costly fix.
5) Driving habit
If you take short trips most of the time, do a bit more warm up at cold start (even during summer). Your vehicle needs to be in operating temperature, usually 10 minutes drive.
Let say the book tells you to change oil every 7k miles, when you do long trips the most, you can stick with 7k interval. You do stop-n-go short trips all the time, you change at 5k interval.
When your cat converter never reaches its operating temperature you have more contamination, more buildups and leftovers.
6) Normal wear
If your mom or your wife loves to throw all kind of food wastes into your garbage disposal, the lifespan can be shortened from 10 years to 2 years.
Cat converter should be made to last the life of your vehicle. If you are the 1st and sole owner of your vehicle and your cat is failing prematurely, that indicates you are not doing maintenance regularly.
Why all these matter just because ideally on a cleaned old vehicle, only air and fuel enter into your combustion chamber and you take only short trips you will have more carbon buildups alone.
When your combustion chamber has do deal with air + fuel + motor oil (because your car is burning oil shown at (4) above), more than just carbon buildups.
If it's facing all 4 (air + fuel + motor oil + coolant), your new cat probably can't handle those and definitely will have premature failure. That's also why I mentioned numerous times that you are urged to deep clean your combustion chamber using berryman 2611 after addressing the root causes and before replacing your cat.
Thread Starter
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Member
Joined: Jul 2025
Posts: 62
you are ABSOLUTELY correct i need to test exhaust back pressure, it melted the cat because there was two plug wells filled with water on the inner two cylinders causing the cat to VISIBLY GLOW from two injectors essentially dumping raw fuel in which is nuts. gramps got the water out the wells, and it ran ok but then slowly got worse till we ended up here. im gonna pull the first o2 out and test it. oh and the PCV DEFINITELY needs replaced lol. you guys are awesome, i really appreciate all your help. im gonna pull the o2 tomorrow, maybe stick a pressure gauge on it. is there any normal pressure range at different RPM to indicate normal pressure vs excessive? foot to the floor the poor thing can do MAYBE 1200 RPM and stalls when i let off. i will also look into a scanner
Last edited by REETKID22; Aug 4, 2025 at 11:10 AM.
Thread Starter
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Member
Joined: Jul 2025
Posts: 62
im gonna pull the upstream o2 out tonight or tomorrow, gonna take a video of how it looks and if i can shine a light or even stick the bore scope down the cat. i also plan on starting it up with the o2 out to see if it runs better.
Senior Member
Joined: Jun 2010
Posts: 16,528
That is one of the tests you can do, but I did not suggest it because ,,first it will be very noisy, and if there is anything close by the hole you will be blowing very hot exhaust out and burn something. Your choice.
Senior Member
Joined: Jun 2010
Posts: 16,528
Soak the nuts securing the exhaust to the manifold with some PB Blaster. I do not suggest WD40 because it evaporates and is best for "Water Displacer"
That's what the WD stands for.
An exhaust system shop would apply heat with a torch and that is not recommended in a home setting due to the fire hazard.
Good auto supply stores like NAPA , usually have spray cans of PB Blaster penetrating oil.
That's what the WD stands for.
An exhaust system shop would apply heat with a torch and that is not recommended in a home setting due to the fire hazard.
Good auto supply stores like NAPA , usually have spray cans of PB Blaster penetrating oil.
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