Hello, I had check engine light come on and had it scan P0171 and P0174. I'm also hearing a loud noise coming from the front of the car when it runs. I'm a newbie and would like to work on the problem first before I take to mechanic. I tried to search the forums but could not find a direct answer. Can anyone help with the first things I need to check. I have a 2004 X-type

 

if memory is correct that is a vacuum leak, check the various vacuum lines for leaks or loose connections. If nothing is visually bad then it may be the IMT gaskets or the upper or lower intake manifold gaskets

 

I agree about the possible vacuum leak. If the noise is a hissing type sound then that would make sense. Can you desrcibe it? It would make sense to get the codes you mentioned if you have a significant vacuum leak.

If you're having trouble tracing the leak or sound, an old mechanic's trick works very well. Get a 4 foot section of 1/4 inch or so vacuum hose. Hold one end in your ear and the other end in the general area of the sound. The louder it is, the closer you are.

If the area is hard to reach. tape one end of the hose to a wire coat hanger or stiff, bendable rod. This will allow you to probe the areas with more accuracy.

A mechanics stethescope that has a removable probe works very well also. The metal probe can help you find other sounds like bad bearings or ticking, knocking sounds. With the probe removed you can do the hose trick easier since both hands are free to move the hose around and both ears can listen.

Good luck.

 

Thanks for the reply I can only hear the loud noise when the car is running at high speed if it's at idle it is just normal sound. I can try to find if there is a vacuum leak. Not sure where the IMT gaskets and upper and lower intake manifolds gaskets are but will try to look.

 

When I have a problem like you do, I use the "Search this forum" button. Give it a shot. Go to the main page for the X-Type forum. At the upper right you'll see two black buttons. One says "Search this forum". Type in "P0171 P0174". I just tried it and there are quite a few threads pertaining to this. Way more information than I have time or knowledge to type out. I'll bet your answer is there. Many times you'll find useful information you were not even looking for.

As far as the noise, I think it's possible that it's unrelated to your codes. If you could describe the noise and when it does it in more detail, you will probably strike a familiar chord with an X-type expert. What does it sound like? What vehicle speed, load, throttle position, rpm does it seem to start or get loudest? Is it's pitch or frequency linear with vehicle speed or engine speed? From what part of the car does it seem to eminate? The more details the better.

Good luck.

 

Raffy, well, I can help you out a few different ways here. First off, when you say a "noise from the front of the car", can you be a bit more specific? This leaves a lot to the imagination. If it is an air sucking sound (like a vacuum), then what I would tell you to do is to remove the cover off of the engine and then if you look a little to right from the center of the engine, you will see a large hose running front to back from the front valve cover to the intake. Remove this hose and look at the back side of it. I bet you will find that this hose is split on the backside. For the moment, you can run to the autoparts place and get a piece of large diameter vacuum hose to get the car back running properly. Then you can stop by your local jag dealership and pick up a new hose (like $15). You would be wanting the "PCV hose". Probably a good time to replace the PCV valve too if you haven't done that in the last 60K miles or do not know when it was last done.

If you want an opinion and possible fix and don't mind a litlte bit of a drive, I live about 2 hours south of you. I'm in Southern Maryland down near California, MD. I would be more than happy to give the car a once over and see if I can determine what is up. Let me know.

 

Thanks for the reply Thermo I'll check this morning if the large hose is the problem and let you know.

 

hi raff, i have checked the codes you said, and it says for both of them system to LEAN , this is the fuel system, hope this helps, peter

 

Thermo, it is not the hose there is no crack or hole in it. Can't replaced the PCV valve it is a dealer only parts and even the dealear has to order it $23.50 not bad but it will take a few days. Although it looks ok, it rattles when you shake which I read somewhere that meant it is still good. In the meantime I have cleaned the MAF sensor and replaced air filter and cleared the check engine light. I hope it stays off for now.

 

Raffy, two more things to check. First off, there is a small line that runs from the top of the intake over to the brake booster. Do a hand over hand of that to make sure you don't have any cracks in it. Specifically look around the bulb in the center of the line. That bulb is a check valve and it is known for cracking and causing a vacuum leak.

The other thing to check is the flex joint between the MAF sensor and the throttle body. If you get a small rip in this, it can also cause what you are seeing.

 

Thanks Thermo, I forgot to say the sound is indeed like a loud vacuum sound and my car has 63K miles on it. I'll check the flex joint between the MAF and throttle body not sure where brake booster is but will try to check also.

 

Hi Thermo I think I found the problem there is a hissing sound coming form the IMT gaskets unfortunately non of the local auto parts carry them. Will have to wait until tomorrow to get them. Thanks again I will post if this fixes my problem.

 

Raffy, yes, that can cause the codes too. Granted, normally they only cause 1 or the other, not both of them. Sounds like you have a hell of a leak. Unfortunately, you can only get the o-rings from the dealership to the best of my knowledge. But, atleast they are cheap ($3 each).

On a side note, replace both. The upper one is easy. The lower one is going to be the one you are going to cuss at some. But, don't fret. The solution is to undo the 2 bolts holding the IMT valve in place, then pull the valve back until it touches the motor. From there, you can access the o-ring and stretch is some to get it over the IMT valve. Then, to put the new o-ring on, slide it under the bottom of the IMT valve and then stretch it slightly to get it back over the IMT valve. From there, you can slide it into the groove where the o-ring should be and reassemble everything.

 

Hi Thermo, I was able to replace both IMT gaskets $8 at the dealer. The Check engine lights is gone for now but the loud vacuum sound still persist. Here are the things I have done so far. Replaced PCV hose $20, replaced air filter 13$, clean MAF sensor, replaced IMT gaskets. I'm thinking of replacing brake booster hose as well but it cost $115.00 at the dealer and did not want to waste money if not needed. Is it possible the sound I'm hearing is not related to the code P0171 and P0174? Thanks again Raffy.

 

P0171 + P0174
lost power whenever speeding over 80mph.
the issue solved by changing a maf sensor.

 

Raffy, what I want you to try is going to the hardware store and get into the plumbing area. You will find some small boxes of clear tubing (tygon tubing). Pick up a box of 1/4" tubing (should cost around $6). Cut off a section about 3 feet long or so. What you are going to do is to put one end of the tube up to your ear as you run the other end around the engine bay, making sure to push the end of the tube down into the openings and whatnot. As you get the tube next to where the vacuum leak is, you will hear it inside of the tubing. From there, you can look at where the end of the tubing is and see where your vacuum leak is. it is possible one of your intake gaskets has failed. Would not be the first one I have seen. But, using the tubing, you will be able to get the location of the vacuum leak narrowed down. If you want help replacing the intake gaskets let me know. A set of upper and lower gaskets will run you about $45 total if you get them at Advanced Auto. If you go to the dealership, plan on spending about $150. Doing the gaskets will be about a 3 hour project.

 

Thermo, I saw a clip in you tube on how to replace upper and lower intake gaskets. Looks like it's not a job for a newbie. I'll take the car to the local auto shop and let them diagnose the problem. I'll post on what they find and what the fix is. Thanks again for all you help.

 

Hi Thermo, Just got the car back from the shop the noise turns out to be front driver side wheel bearing. They can't give me a quote until Monday said the dealer is closed today. My question is. Is this a difficult or fairly easy job to do? I'll search the forums to see what I can find. Thanks again.

 

Raffy, the job overall is not hard, but you have to get the half shaft out of the bearing and pretty much pull the spindle off. Getting the half shaft out can be the challenge. Some come out easy, others, well, choice words are said. If the car is at the shop, might as well have them do it.

If you want to do the gaskets, come on down. I have no problem doing that job. It will save you a lot of money in the long run. Once you see what is going on, you will laugh. I will teach you all that you need to know.

 

Sorry it took so long to reply, thanks for the offer Thermo I might take you up on your offer when its time to replace the gasket. As of now the CEL is gone and noise is gone. For those who searching the forums for info.
For P0171 and P0174 the fix was IMT gasket were replaced $8 at dealer.
For the loud noise, front driver side wheel bearing was replaced $300.00 auto shop.