I have a 2004 Jaguar S-Type V6. I purchased it about 8 months ago and never have had a problem until recently. The only problem I had until now (I do not think it is related, but have no clue if it is related or not) was a short metal rattling noise only once in a great while when I started the car. The noise would only happen right after I had let go of the key to start the engine, and end within 1 second of it starting. The sound never seemed to lead to anything else, but it did increase in frequency not duration though, but has almost stopped as of recent (only has happened once in the last 2 weeks).

Valvoline...

I went to a Valvoline to have my oil changed (I know a mistake) and they made some rather large mistakes which may or may not have a hand in the current problem. I am going to detail them just in case it is related or helps diagnose the problem.

They drained my current oil and put 5W 30 Synthetic Oil in and went to show me the air filter. The guy accidentally ripped the entire air filter housing, vacuum tube, clamps etc off. He tried to quickly put it back on before I said something and started hitting it with a wrench to have it fit back on. I told him to stop, and use a screwdriver to which he apologized and did, but had a lot of trouble with it. After everything was done he told me to start my car, but it said "Restricted Access" and would not start. He then said he forgot to put the oil cap on, and told me to restart it, and it worked fine.



The problem...

I noticed the problem about 1-2 days after leaving Valvoline. The car's RPMs would be fine at idle around 750 RPMs but when I was driving around 35 - 45 MPH and slowly accelerating the RPMs would fluctuate or jump up and down 250 RPMs.

I then took it to a local shop that has worked on it before, and they said that it appeared Valvoline had gotten oil on the Mass Air Flow sensor so they cleaned it, and noted that the MAF sensor may need replaced if it continues.

I took the car home and for the first 1 - 2 days it ran fine, then on day 2 or 3 it started with the RPMs jumping about and down by 250 RPMs when slowly accelerating from 35 - 45 MPH. Also when slowing down the RPMs would go down choppy in incriments of 50 - 100 RPMs, and not smoothly like it used too. Each day it would get a little worse and now the car seems to be shifting at odd times, and the car is starting to hesitate when driving (almost like you hit a small puddle of water when driving).

I went to open the housing containing the air filter and noticed that attached to the front bottom of the air filter housing there was around a 1" plug with nothing plugged into it. I took a pic but do not know how to upload the pic. Anyway I was not sure if there was or is suppose to be something plugged in there, but currently there is not.

I went on to test the MAF by flicking the MAF while the car was running and the car studdered and stalled other times. I also noticed by simply moving around the vacuum hose that at times was enough to stall the car as well. When I ran the car without the MAF plugged in it failed to start once and started and stopped another time, and two other times started fine, but RPMs dropped in a choppy way around 100 RPMs at a time and not smoothly.

Any ideas on

1. Is something suppose to be plugged into the electrical outlet thingy on the bottom front of the air filter housing?

2. What is causing the RPMs to fluctuate and the car to studder when slowly accelerating?

 

Need atleast 10 posts to utilize all functions on here including adding pics. Could be number of things, but that pic will surely narrow it down to the problem. Could be a crack in the filter housing or bad MAF Did you hook up a car scanner to read any codes off it? IF so, list the codes on here and someone will chime in and let you know.
Good Luck.

 

Thanks for the reply.

I looked at the receipt from the shop that cleaned the MAF sensor and the codes were on the receipt as well.

Scanned Codes DTC'S P1260, 1582, 112 AND C1165 SET

 

I also have has the DSC and ABS faults come on and go off when I restarted the car. It happened twice. Not sure if it is related to the RPM problem or not, but wanted to provide any info I could think of.

 

Do you mean this connector:



Sorry for the crappy pic. But nothing is plugged into it.

As far as the RPM problem, make SURE the air filter box top is sealed correctly and also look check for vacuum leaks, some of the lines get very brittle and just a bump could crack one. Heres a link to have a look at: https://www.jaguarforums.com/forum/s...-w-pics-52720/

ABS and DSC faults could be a failing battery. Do a seach on "failing battery". If its an original Jaguar battery, I would start there.

 

You should document everything that it takes to fix it because you may have a claim against Valvoline.

You may have multiple vacuum leaks, and inducing a further leak takes it over the limit for running.

And *what* was being hit with the wrench?

In addition, go over every connection that was involved in the ripping out of the airbox+.

It's starting to sound like the only safe thing to do is to instruct oil change places to not touch anything ... just do the oil change. Of course, that can be softened up by saying that it is a specialised procedure ... which it is.

 

Battery is a suspect, for sure. Read recent posts carefully not least about NOT getting it tested as good when it actually isn't,

 

Thanks everyone for the replies...

joycesjag yes that is it.

I will get the battery tested too, thanks.

How do I check for vacuum leaks? And is there somewhere to check first that is most likely the vacuum leak is coming from? Do the symptoms seem more like a vacuum leak or a MAF sensor going bad?

Thanks again.

 

It could be quite a few things, as others have said. One thing is some of the trouble codes you posted do not make sense.

Oh, BTW, welcome neighbor! Well, I say neighbor if the you actually mean Green, Ohio as in the city... LOL

That said, if you need some extra hands, eyes to look at it, let me know...I've got a code scanner as well, just not the fancy, hook it to your laptop one that others have....

 

Again: be wary about testers - they tend to say "good" but be wrong.

Lots of threads about leaks, so Search

Also this https://www.jaguarforums.com/forum/s...ics-faq-52720/

 

3rd time this link posted in this thread:

https://www.jaguarforums.com/forum/s...ics-faq-52720/



Difficult to say just yet.

 

I hate to possibly bear bad news, but what you describe sounds like a failed torque converter. The 35-45MPH, 250 RPM jump is converter dead out. If someone has a graphing scantool, they can watch the engine RPM and Road Speed or trans input speed together. If the engine RPM is jumping up and down and the other speeds do not, that means the torque converter clutch is slipping.

Ouch!

The connector on the air filter box is just a holder for an unused connector on the V6 models.

Cheers,

 

Steve a very small vacuum leak in these vehicles with the ZF6HP26 gearboxes which OP has are known to cause "lurching" or what OP says "car seems to be shifting at odd times, and the car is starting to hesitate when driving".

My bet is still on a vacuum leak.

 

I'm aware of that condition. Precisely why I added the best way to confirm the converter. Remember, if the converter is locked, the engine is locked to the wheels, basically. The magnitude of the RPM fluctuation seals it for me. I feel 250 RPM is too much for a small vacuum leak.

Cheers,

 

That unused plug is interesting! It looks exactly like the connection on my STR that controls the extra flap to the air box that opens up under full throttle. The 6 cylinder cars don't have this but maybe Jaguar uses the same air box bottom across the S Type line up?
.
.
.

 

Bingo! We have a winner!

[Absolutely NO reference being made to Charlie Sheen]

Cheers,

 

My 05 4.2 doesn't have the small flap inside the airbox like in the STR

However she likes her air, when the car is running I can place my hand in front of the air inlet dam and it sucks like a hoover.

 

Thanks again everyone. I will try to test for a vacuum leak and will post the results tomorrow afternoon.

JOsworth yes please I could use any help I could get as I am a newbie to this whole thing. I cannot PM until 10 posts I believe so how can I get in touch with you. Thanks again. I live like 5 minutes from Akron, and could even meet you or you could stop by my house if you would like just let me know, and thanks again.

 

Oh and one more thing....

I noticed that anytime I mess with the vacuum hose and air filter housing to check things such as MAF etc when I reattach everything the car runs better for a day or two before slowly getting worse again. Does that help at all?

 

Hey no problem, shoot me an e-mail jeff03ex@yahoo.com . It's supposed to be warmer this weekend! We can look it over.. To be honest, I really think it's a bad sensor or something loose. We can hook my scan tool up and see if it shows anything.. Your other post about it being "better" then getting worse makes me think something is not sealed properly...

You just have to promise not to laugh at the fact that I have a Chrysler now... LOL