Check compression. If you have low readings in two adjacent cyliners you may have blown the head gasket between the cylinders.
Headgasket?
This is a continance of my earlier post on my timing belt breaking and later, driveability issues on the Daytona, with 2.5L.
Checked vac lines again this a.m. and found one of the egr solenoid lines not hooked up, so I did so. checked plugs, and they were not fouled.
Took it for a full road test, and it ran great for a couple of miles at highway speed, then at a stop, the idle roughened and progressed to rough running at road speed. Made it home, with the idle sounding as if it had a Hi Performance camshaft in it. Sitting at idle, white smoke appeared out of the tailpipe, and smoke in general was coming out of the throttle body. Oil pressure dropped also. Tried one restart, and very rough idle with no oil pressure. Shut if off immediately at that point. I do see evidence of oil leaking from head gasket.
No water in the oil, fwiw and no oil in coolant.
I do have a Mopar Perf headgasket stocked away in the shop...should I go ahead and change it, or might the engine be toast?
Checked vac lines again this a.m. and found one of the egr solenoid lines not hooked up, so I did so. checked plugs, and they were not fouled.
Took it for a full road test, and it ran great for a couple of miles at highway speed, then at a stop, the idle roughened and progressed to rough running at road speed. Made it home, with the idle sounding as if it had a Hi Performance camshaft in it. Sitting at idle, white smoke appeared out of the tailpipe, and smoke in general was coming out of the throttle body. Oil pressure dropped also. Tried one restart, and very rough idle with no oil pressure. Shut if off immediately at that point. I do see evidence of oil leaking from head gasket.
No water in the oil, fwiw and no oil in coolant.
I do have a Mopar Perf headgasket stocked away in the shop...should I go ahead and change it, or might the engine be toast?
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I agree with Cudapete, Russ. The 2.5 has proven to be one of the best engines Mopar has ever had, so if it were me, I'd go ahead and do the compression test and most likely replace the head gasket. Just be sure to get some new head bolts if you do. I'm not sure, but I think those are torque to yield and can't be re-used.
Bolts are torque to yield but they can be re-used if they aren't stretched. Mine weren't when I did my HG but I used new ones just the same. You need washers to go with the bolts if the set you get doesn't have them. A HG may not show coolant and oil miximg, mine only had bubbling in the CRS tank.
I have confirmed I do have oil pressure at least. The connector to the sender had come loose. Started it briefly again, and immediately fouled the plugs. I am now suspecting the AIS motor is stuck. I pulled it and the passageway looks clean. flused with carb cleaner just in case. With the connector on the AIS motor, turning the key on produces a slight thump in the motor, but no movement of the pintle. Is this normal?
Tested the AIS motor again, and the pintle actually shot out of the end. Screwed the pintle back into the motor to where it protruded less than one inch, per the FSM and reinstalled it. Car still idling very rough. Checked plugs, and two were carbon fouled, two were wet with fuel.
White smoke = head gasket. When mine failed, I had a small oil leak at the driver's side rear corner that puddled on the transmission case. When it finally went, there was a rough idle and white smoke, and coolant dropped and it bubbled furiously with the radiator cap off. No cross-mix of fluids. The gasket failed at the passenger corner rear of the gasket, between the cylinder seal and a coolant passage. The head was fine.
Definitely, always use new bolts. They are torque-to-yield, and therefore when torqued as directed, they have yielded, whether you can see it or not. $35 will get you a new set.
Definitely, always use new bolts. They are torque-to-yield, and therefore when torqued as directed, they have yielded, whether you can see it or not. $35 will get you a new set.
This whole thing is very strange, in that it all showed up when the timing belt broke. On the last two starts, no more white smoke, but the TB seems to be loading up with fuel. I'm going to borrow the AIS off my Lebaron and see what it does on the Daytona.
No luck. The AIS off the Lebaron did no good. Car starts and runs, but is obviously loading up with fuel. I can rev it up to about 2000 for example, then let off to an idle and it puffs black smoke. Barely idles. checked timing again, and its on 12, so it didn't jump timing.
Clear codes, try to run it and check codes again. I'm thinking there's still a vacuum leak that's throwing the MAP sensor off. It can behave very badly. Check the power brake booster hose and the PCV hose, too, for cracks or a poor fit.
No codes are showing now.
Thanks for responding. Since last update, I found several wires in the large, black connector that leads to the AIS and TB temp sensor that had melted together with some bare spots. I was confident I had found the problem, but I separated them all, cleaned the soot off the spark plugs, and still no improvement. I also swapped out the computer from my Lebaron, with no improvement. Now, car starts right up, but does not have any idle flare, indicating a problem with the AIS, and is still idling very rough.
Did a good repair of the PCV elbow with hose and a clamp yesterday, but no help. I did just discover that I did not have the line from the intake to the PCV tied in to the canister purge, so I corrected that, but still no change. I really think all the vac lines are now good.
I also tried another ignition coil, no help. I did find green corrosion in the connector for the fuel injector. Cleaned it, and ho help.
Yesterday, when the car was idling better than it is today, I unplugged the vac line to the MAP, and it went crazy. Plugged it back in, and car idled well. Also tried a different MAP, with no change.
Checked the vac line to booster, and it is good.
Thanks for responding. Since last update, I found several wires in the large, black connector that leads to the AIS and TB temp sensor that had melted together with some bare spots. I was confident I had found the problem, but I separated them all, cleaned the soot off the spark plugs, and still no improvement. I also swapped out the computer from my Lebaron, with no improvement. Now, car starts right up, but does not have any idle flare, indicating a problem with the AIS, and is still idling very rough.
Did a good repair of the PCV elbow with hose and a clamp yesterday, but no help. I did just discover that I did not have the line from the intake to the PCV tied in to the canister purge, so I corrected that, but still no change. I really think all the vac lines are now good.
I also tried another ignition coil, no help. I did find green corrosion in the connector for the fuel injector. Cleaned it, and ho help.
Yesterday, when the car was idling better than it is today, I unplugged the vac line to the MAP, and it went crazy. Plugged it back in, and car idled well. Also tried a different MAP, with no change.
Checked the vac line to booster, and it is good.
Did a compression check, with engine warm. Cyl 1, 130; 2, 136; 3, 125; 4, 124.
Also pulled the fuel injector, cleaned it and replaced its O ring. Again cleaned soot off the spark plugs.
No improvements. Car acts as if it is not firing on all cylinders, or a plug wire is crossed, but no wires are crossed. All plugs seem to be firing, because all four get covered in soot after being cleaned. However, with car idling, I pulled one plug wire at a time, and did not notice any change in idle quality.
Also pulled the fuel injector, cleaned it and replaced its O ring. Again cleaned soot off the spark plugs.
No improvements. Car acts as if it is not firing on all cylinders, or a plug wire is crossed, but no wires are crossed. All plugs seem to be firing, because all four get covered in soot after being cleaned. However, with car idling, I pulled one plug wire at a time, and did not notice any change in idle quality.
I know it's probably a stupid question, Russ, but I'm going to ask it anyway. Have you taken a good look at your rotor button and plug wires under the cap? Sometimes the wires get pitted and need to be rotated 180 degrees to the better contact side. Just replace the rotor button with a new one. They're cheap enough. Heck, for all I know, you may have an extra one around there already.
Also, might be a good idea to recheck the valve timing. When you replace a belt before it breaks, it's hard to be off, but after a belt breaks or slips, there is the possibility of not aligning the marks correctly.
I would bet it's a HG problem. Even if your valve timing was off, compression would moVe up or down evenly over all cylinders, i.e. they would all be high or low. The 136-125 in particular could be where your break is.
That's not a likely behavior at all. Usually a head gasket failure is one or two cylinders, not across all four; is between oil and coolant, coolant and cylinder, or oil and cylinder. Those compression readings are normal. A 10% variation between cylinders, and up to 25% below new readings, is within spec.
A compression test may be inconclusive for many of the 2.5 HG failures simply because the failure is often just a hairline crack in the steel fire ring. The cylinder may pass the compression test, but a small amount of combustion gas can pass through to the cooling system passageway adjacent to the cylinder. Likewise, when a warmed engine is turned off and the cooling system is still pressurized, a drop or two of coolant can pass through a split HG and get into a cylinder. A compression test to diagnose a ruptured gasket would certainly show a problem but a ruptured gasket is usually not the typical 2.5 HG failure.
The best test is to use a product that detects combustion gasses in the coolant overflow container, unless you already see streams of bubbles present in the container; then it is pretty obvious.
Sometimes the HG hairline fractures that show up in the fire ring (that surrounds the cylinder) are so small that they don't cause noticeable leakage until the engine has warmed up. When I am checking for the HG problem, I watch the overflow container right after starting the engine when it is cold and continue to watch for 15+ minutes while the engine fully warms up. Of course, you must make sure that there was no air in the system from any previous work where the system had been opened.
Keep in mind that any coolant that has passed through the exhaust may have poisoned the O2 sensor which will cause a bad running engine.
The best test is to use a product that detects combustion gasses in the coolant overflow container, unless you already see streams of bubbles present in the container; then it is pretty obvious.
Sometimes the HG hairline fractures that show up in the fire ring (that surrounds the cylinder) are so small that they don't cause noticeable leakage until the engine has warmed up. When I am checking for the HG problem, I watch the overflow container right after starting the engine when it is cold and continue to watch for 15+ minutes while the engine fully warms up. Of course, you must make sure that there was no air in the system from any previous work where the system had been opened.
Keep in mind that any coolant that has passed through the exhaust may have poisoned the O2 sensor which will cause a bad running engine.
I replaced plugs, wires, cap and rotor with no improvement...I know it's probably a stupid question, Russ, but I'm going to ask it anyway. Have you taken a good look at your rotor button and plug wires under the cap? Sometimes the wires get pitted and need to be rotated 180 degrees to the better contact side. Just replace the rotor button with a new one. They're cheap enough. Heck, for all I know, you may have an extra one around there already.
I have checked timing several times during all of this, and it holds where I last set it. In this case, it's at 12.Also, might be a good idea to recheck the valve timing. When you replace a belt before it breaks, it's hard to be off, but after a belt breaks or slips, there is the possibility of not aligning the marks correctly.
thanks John...will watch for bubbles in the coolant tonight when I work on it. I see your point about the o2 sensor. I will recheck for codes also.A compression test may be inconclusive for many of the 2.5 HG failures simply because the failure is often just a hairline crack in the steel fire ring. The cylinder may pass the compression test, but a small amount of combustion gas can pass through to the cooling system passageway adjacent to the cylinder. Likewise, when a warmed engine is turned off and the cooling system is still pressurized, a drop or two of coolant can pass through a split HG and get into a cylinder. A compression test to diagnose a ruptured gasket would certainly show a problem but a ruptured gasket is usually not the typical 2.5 HG failure.
The best test is to use a product that detects combustion gasses in the coolant overflow container, unless you already see streams of bubbles present in the container; then it is pretty obvious.
Sometimes the HG hairline fractures that show up in the fire ring (that surrounds the cylinder) are so small that they don't cause noticeable leakage until the engine has warmed up. When I am checking for the HG problem, I watch the overflow container right after starting the engine when it is cold and continue to watch for 15+ minutes while the engine fully warms up. Of course, you must make sure that there was no air in the system from any previous work where the system had been opened.
Keep in mind that any coolant that has passed through the exhaust may have poisoned the O2 sensor which will cause a bad running engine.
No, Russ, I meant the valve timing, not the ignition timing. The relationship between cam, crank and intermediate pulley marks when you changed the timing belt.I have checked timing several times during all of this, and it holds where I last set it. In this case, it's at 12.
Oil seepage from the gasket is not normal either. If you have bubbles, that with the oil seepage would be enough to make me do a head gasket. The numbers are okay now that I look at them again, sorry about that.
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