Hi Everyone! Just wanted to introduce myself and my new family member J I now own a 1995 Grand Marquis GS. It is nice to have a ford product in the family again, only wish it was a P71... To give you a little background, she was owned by one owner who always took it to the dealer. It has 44,000 miles on it, but did not come with any service records as the owner misplaced them. I was wondering if anyone has any insight for a few issue’s, the most disconcerting of which is…
Once the car heat’s up it begins to hesitate and shudder as your building rpm's. As soon as you let off the gas and plant your foot again the hesitation is gone. When you start to slow again and give her more rpm's the shudder comes back…
The engine run’s fairly smoothly so I highly doubt that it is caused by misfires. Unfortunately not knowing the car’s history I will need to change the plug’s and perhaps some coils but this issue seems far more serious. I am wondering if it could be the tranny? This car has the 4R70W transmission. In researching my issue I found something that seems very logical and similar in nature. They call it “torque converter shudder” and suggest an additional transmission oil cooler to hinder the breakdown of the oil/friction material. Wikipedia states…
“A 20,000+ GVW cooler is highly recommended for all vehicles. Breakdown of the transmission fluid often results in "converter shudder" (feels like driving over rumble strips) where converter tries to maintain a steady slip rate during lock-up, but alternates between slipping and grabbing. Frequent fluid changes, especially when used for towing, are the single best method to prevent shudder. Shudder occurs because the torque converter never fully enters "lock-up", but is designed to slip slightly during steady-state operation. The reason Ford decided to use "Steady-state-slip" is often discussed but no complete answer has been found.”
I will certainly change the fluid to Mercon V as soon as possible but does someone know the part number of this additional tranny oil cooler?? Hopefully this will solve the problem but if anyone has some insight into this issue or has other theories I would appreciate the information!!
Also can anyone recommend an inexpensive scan tool / software to detect trouble codes? I know Pep Boy’s or Auto zone will scan the car’s for free but I like to be able to see the code’s myself.
Thanks,
Rhonda
If the spark plugs and fuel filter haven't been changed, that would be a good idea. Just make sure to get double platinums and use a torque wrench. Too tight and the aluminum head expands and pulls the threads out. Until you get a scan tool, at least go to Autozone and check for codes. Your car has OBD2 so their scanner will work. Another thing that I would suggest is to clean the MAF with the special MAF cleaner. The MAF can cause symptoms like yours. Your car has a drain plug in the torque convertor so with the filter it will take about 10½ qts. I wouldn't worry about the cooler unless I was going to tow a trailer.
If the spark plugs and fuel filter haven't been changed, that would be a good idea. Just make sure to get double platinums and use a torque wrench. Too tight and the aluminum head expands and pulls the threads out. Until you get a scan tool, at least go to Autozone and check for codes. Your car has OBD2 so their scanner will work. Another thing that I would suggest is to clean the MAF with the special MAF cleaner. The MAF can cause symptoms like yours. Your car has a drain plug in the torque convertor so with the filter it will take about 10½ qts. I wouldn't worry about the cooler unless I was going to tow a trailer.
Rtg143,
Thanks for sharing your thoughts, sound's like great advice and I will start with your suggestions.
If the spark plugs and fuel filter haven't been changed, that would be a good idea. Just make sure to get double platinums and use a torque wrench. Too tight and the aluminum head expands and pulls the threads out. Until you get a scan tool, at least go to Autozone and check for codes. Your car has OBD2 so their scanner will work. Another thing that I would suggest is to clean the MAF with the special MAF cleaner. The MAF can cause symptoms like yours. Your car has a drain plug in the torque convertor so with the filter it will take about 10½ qts. I wouldn't worry about the cooler unless I was going to tow a trailer.
rtg143,
I resolved the hesitation issue. After changing the tranny filter and adding 10 1/2 quarts of Mercon the hesitation was still there. So I cleaned the MAF sensor, still no better. Then I changed the fuel filter and the hesitation got better but it was not completely gone. So I went to autozone and no codes came up...hmmm. Then I got under it when it was fairly dark to see if the plug wires were ok and sure enough they were arcing. Changed the plug wires and the car run's perfectly now. No hesitation whatsoever.
I resolved the hesitation issue. After changing the tranny filter and adding 10 1/2 quarts of Mercon the hesitation was still there. So I cleaned the MAF sensor, still no better. Then I changed the fuel filter and the hesitation got better but it was not completely gone. So I went to autozone and no codes came up...hmmm. Then I got under it when it was fairly dark to see if the plug wires were ok and sure enough they were arcing. Changed the plug wires and the car run's perfectly now. No hesitation whatsoever.
Thanks again for your feedback!
Rhonda
Something like this would cost most people thousands of dollars to figure out.. Glad you caught it before buying a transmission or anything expensive.
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To give you a little background, she was owned by one owner who always took it to the dealer. It has 44,000 miles on it, but did not come with any service records as the owner misplaced them. I was wondering if anyone has any insight for a few issue’s, the most disconcerting of which is…
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