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Discussion Starter #21
I occasionally do the same thing- pop the hood after the freeway drive to let the hot air out. I don't know if it does any good, but extended heating of rubber, plastics, etc. isn't beneficial. We're some 440 miles south of you, and around here it's the damn ground squirrels that are destructive.
Yes, it's always good to let the engine and the extended heating of rubber, plastics, etc.to cool off. In my case it prevent the damn mice to use my car engine area as free housing! We have the damn ground squirrels too! Both such nuisance, but they are here to stay, so we have to take all measures that we can to protect our cars and home.
 

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There is a possibility of an air leak at the flexible intake hose between the airbox and throttle body or at the throttle body hard plastic tube. They have rubber gaskets that can bind when installed and cause a leak. It's this hose and the one it connects to at the top. If not them, there is an air leak somewhere and the mechanic should be able to find it. BTW, for all of the work done, the prices are great at your shop!
97629
 

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Discussion Starter #23
There is a possibility of an air leak at the flexible intake hose between the airbox and throttle body or at the throttle body hard plastic tube. They have rubber gaskets that can bind when installed and cause a leak. It's this hose and the one it connects to at the top. If not them, there is an air leak somewhere and the mechanic should be able to find it. BTW, for all of the work done, the prices are great at your shop! View attachment 97629
Thank you PZ, greatly appreciate it. And, yes, you are right on. He checked all the valves, cleaned the MAF, throttle body, checked every connectivity for air leak, etc. test drove my car, code went away. I'm grateful to him, to you and everyone on this forum who help me out with sound and great solutions/advises. You guys are simply the best!

I'm taking him a nice bottle of Pinot Noir as a gesture of my appreciation.
 

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Discussion Starter #24
Thank you PZ, greatly appreciate it. And, yes, you are right on. He checked all the valves, cleaned the MAF, throttle body, checked every connectivity for air leak, etc. test drove my car, code went away. I'm grateful to him, to you and everyone on this forum who help me out with sound and great solutions/advises. You guys are simply the best!

I'm taking him a nice bottle of Pinot Noir as a gesture of my appreciation.
Hi Pz & All: I wanted to provide an update and ask for insights and recommendations.

After all the repairs, timing belt change, etc., for a couple of days my car was doing fine, but then I started hearing some strange noise (like whistle) while driving. I pulled over, opened the hood and noticed it is coming from the upper part of my engine near the coolant tank area on the right hand side. Now, that I know what the part is called, it was the PCV, which was replaced when my mechanic was doing the other works, which I've written about them above. I took my car to his shop and after examining the situation,he said that the PCV is defective, ordered a new one and replaced it the same day.

No engine light for a few day, but then my engine light came on last Saturday and since my mechanic is closed on weekends, to put my mind at ease, I took it to O'Reilys (auto parts shop, they offer free engine light scan) for a scan and the codes were P0491 & P049. Plus some details code definition, please see pics below.

Took my car to my mechanic on Tuesday and told him about the codes and he also ran his own scan and apparently there was a leak some where, which he fixed. Cleared the codes and said, let's keep eye on the engine light to see what needs to be done. In the meantime, my car starts just fine and runs softly/quietly when driving on freeways, streets, etc., except that when stopped at intersections waiting for the light to change, my car engine feels running high (rough idle?). My engine is not shaking at idle, it just feels its running higher than usual.

In the morning when I start the car, the idle is at 12 and then once the car is warmed up goes down to 7.

I did some research on Google and here is what I found out: 'A misfiring engine is among the most common causes of a rough idle. You may notice your car idling roughly when it's in "Park" or when you're driving it and stop at a stoplight. A rough idle can be caused by damaged spark plugs or spark plug wires or a burned-out valve.'

I changed my spark plugs 3 months ago or so, changed PCV if what the burned-out valve means.

I appreciate any help you all can provide. I just want to make sure the high idle will not damage the Cat-Converters or anything else. My car is 2003 Passat V6 w/ 2.8 engine, 258K mileage. I only put super unleaded gas in my car. Also, syntactic oil only, check my engine oil to make sure oil is at the indicated level.

Thank you so much in advance.
Ellie
 

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The 'burned valve' most likely refers to the actual intake and exhaust valves (total of five per cylinder) which, if eroded at the sealing surface, will leak. Not a concern for your engine in my opinion.

If you don't do so already, dump a container of Chevron Techron fuel injector cleaner right at your next fill-up. At one time at least, it was the only additive that Audi recommended using. If your fuel injectors are original, and have accumulated gummy deposits, they might respond to the Techron. I've got 223,000 on my A4 and every so often use that.
 

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Discussion Starter #27
Do you have codes now, or you think it just idles high when cold?
The last codes were P0491 & P049 and both were cleared (apparently, there was air leak some where, which he fixed). These codes came up (engine light too) a couple of days after the defective PCV was replaced.

While researching on Google, I came across this 'a faulty or clogged PCV valve may cause the engine to consume oil due to a lack pressure relief. This may eventually cause problems with the catalytic converter as well due to the car’s inability to expel the exhaust gases properly.'

The defective PCV was replaced within a day and I did not drive my car after I heard the noise, except driving to his shop.

Attached pictures are turning on my car 1st (see idle at 11 or 12) and then idle at 8 after car warmed up. I checked the exhaust when turned on the car this morning and air was coming out of the exhaust pipes and after the car warmed up the air was reduced (no smoke coming out of the exhaust at any points). I am worrying the defective PCV, which was replaced might have damaged something as I have noticed the oil level goes down pretty quickly,when I check it and this was not the case before.

Also, posting a pic on changed PCV.

Thank you.
 

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Discussion Starter #28
The 'burned valve' most likely refers to the actual intake and exhaust valves (total of five per cylinder) which, if eroded at the sealing surface, will leak. Not a concern for your engine in my opinion.

If you don't do so already, dump a container of Chevron Techron fuel injector cleaner right at your next fill-up. At one time at least, it was the only additive that Audi recommended using. If your fuel injectors are original, and have accumulated gummy deposits, they might respond to the Techron. I've got 223,000 on my A4 and every so often use that.
Thank you ylwagon! I took this advise, which you provided a while back and I do that. Also, my fuel injector was replaced 3 years ago.
 

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In the past two weeks, I had noticed when cranking the car in the morning, sometimes it starts very quickly, sometimes requires a few more cranking.
I am guessing it has gotten colder in the last two weeks?
Does it have a harder time starting the colder it gets?

ECT sensor is a good starting place, and only a $10 part.
 

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If you still have the engine codes coming back, I expect you have a small vacuum leak in the SAIP system This would be a thin hard plastic line in your last 2 pictures. It's running along the electrical harness at the back of the intake manifold (just in front of the new blue hoses), then under the coolant tank to a large round silver valve (combi valve) on the back of the engine. The other side goes to a matching valve under the plastic flex tube to the intake.
Here is a pic of where it attached to the T, has a short rubber hose and then the plastic hose. From there is goes to each combi valve:
97714


The plastic then connects to a rubber line again right before the valves. Then can be reached with the plastic covers and intake hose off the engine. Here is a pic of both valves from the back of the engine:
97715

97716
 

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Don’t worry as long as it runs smoothly and you have no check engine light. I can’t find anything written for VW, but on MB’s of the same generation, the cold idle is faster in order to warm up the catalytic converter sooner. I am positive that Audi engineers would talk occasionally with MB engineers.

You can see here that many Passateer’s who have gone before you have noticed the same thing:
 

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Discussion Starter #32
I am guessing it has gotten colder in the last two weeks?
Does it have a harder time starting the colder it gets?

ECT sensor is a good starting place, and only a $10 part.
Temp. in Santa Cruz mountains is still in low 70s (today was 82) and in the morning 45-55. No problem starting. The engine feels running high when stopped at intersection for the light to change.
 

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Discussion Starter #33
Don’t worry as long as it runs smoothly and you have no check engine light. I can’t find anything written for VW, but on MB’s of the same generation, the cold idle is faster in order to warm up the catalytic converter sooner. I am positive that Audi engineers would talk occasionally with MB engineers.

You can see here that many Passateer’s who have gone before you have noticed the same thing:
That's good to know. No problem with starting the car in the morning and now I better understand how the idle works. The engine feels running high when stopped at the intersection waiting for the light to change. Also have noticed the oil consumption have gone up. So, that's why I got worried.
 

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Discussion Starter #34
If you still have the engine codes coming back, I expect you have a small vacuum leak in the SAIP system This would be a thin hard plastic line in your last 2 pictures. It's running along the electrical harness at the back of the intake manifold (just in front of the new blue hoses), then under the coolant tank to a large round silver valve (combi valve) on the back of the engine. The other side goes to a matching valve under the plastic flex tube to the intake.
Here is a pic of where it attached to the T, has a short rubber hose and then the plastic hose. From there is goes to each combi valve:
View attachment 97714

The plastic then connects to a rubber line again right before the valves. Then can be reached with the plastic covers and intake hose off the engine. Here is a pic of both valves from the back of the engine:
View attachment 97715
View attachment 97716
Thank you PZ. Took screenshot of your post and will show it to my mechanic.
I'll provide update afterward. My worry is about my engine running high at the intersection waiting for the light to change. Otherwise, car is running just fine.
 

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A vacuum leak can cause a higher idle, but it generally throws some codes too. This is why I’m going with the “normal” scenario. It seemed to match what my car does when I checked it yesterday.
 

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Discussion Starter #36
A vacuum leak can cause a higher idle, but it generally throws some codes too. This is why I’m going with the “normal” scenario. It seemed to match what my car does when I checked it yesterday.
Thank you Hirnbeiss, I'll share this information with my mechanic, so that he can check it out.
 
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