Dodge Nitro Engine Whistling Resolved

[rickaren]

R/T Engine Whistling

NOTE: This pertains to the 4.0 Nitro Engine Only


Nearly all R/T Nitro owners may notice an engine “Whistling” noise under acceleration. Like me, many have satellite radio volume high and their windows up, so they don’t hear it or care. This all changed when I added the MOPAR CAT-BACK-exhaust system


http://www.dodge-nitro.com/dodge-nit...-exhaust-2564/

and the MOPAR CAI unit.

http://www.dodge-nitro.com/dodge-nit...nstalled-2359/

I now want to hear the engine noise and do drive my Nitro more aggressively at higher RPMs.

If you follow many Internet Sites as I do you will find many complaints on this issue from Nitro owners. From what I can see many Dealers just brush this off saying this noise is just the “nature of the beast” and nothing can be done and all Nitros on their lot sound the same and have this whistling noise. Up till just recently they were correct!

After many Dealers replaced alternators and other parts with no luck a Factory Rep figured it was in the design of the head gasket used on the 4.0 Nitro engines that is also used in some minivans mounted sideways. The placement and large engine cover on those vans reduce any whistling noise complaints from those owners.

It has been reported that the oil passages are smaller in the original 4.0 head gaskets and when hot oil is pumped through them a venture effect cause the whistle. It is also said that the 3.5 HO head gaskets were used on the 4.0 engine and just maybe the 4.0 Nitro engine should have had their own head gasket!

I have read that a newly designed head gasket is now being installed on the 4.0 from the factory at the Trenton Michigan Engine Plant. The date is something like August of 2008. I’m sure someone at Chrysler knows s the exact date but that would be 2009 Nitros, NOT any 2007 or 2008s!

I took my Nitro in expecting a hassle. To my surprise the Service Writer didn’t want to test drive it saying he knew about the “Whistling” but had not known anything about this fix, with head gaskets. I gave him the part numbers I had found to correct this issue (4792753-AD & 4792752-AD) but when he went to the parts department to order he found they had been changed again to 479275353-AE & 4792752-AE.

He told me to bring the Nitro back in two days and they would start on it. I did, but one day later he called back and told me I might as well pick it up since the new gaskets are not scheduled to be released for another 3 or 4 weeks.

It sounds believable since I did get a copy of a repair order that I signed stating these gaskets are verified as ordered. I suspect they got paid to check out serial numbers and got paid and received approval to do this repair from Chrysler.

I will follow up after this repair has been performed, but I am hopeful that this will correct this issue. Since my Nitro only has 9K miles there was no issue with mileage, but I suspect it may only be available for the first 36,000 mile or 3 years. It is still not listed as a TSB as of this date.

[rickaren]

Special ordered head gaskets are in. Nitro went to shop today for install. Will update.

[rickaren]

OK got my NITRO back from my Dealer yesterday after they installed these new head gaskets per my request. They did a great job, even replaced the water pump just-in-case, since it was already taken off. Everything was done at no charge under warranty.

I guess I am not totally happy with the results, but since I have only driven it 10 miles or so, maybe I will change my opinion. If I do I will re-post. See I have had many many high performance vehicles and love their engine noise. Maybe I expected too much but on hard acceleration at 5,000 RPM or more there is still a screeching noise from the engine. It was there before adding the exhaust or CAI so they are not the cause. Maybe it is some secret built-in governor put in R/T engines by Chrysler to tell us to slow down, these engines have a Lifetime Warranty! Ha Ha

[MyBluNITRO]

Hey Rick. Mine has had the whistle since new. I now have 30k + miles.
I have pretty much gotten used to the noise. I still can't hear it with the windows up, so I don't think it is as loud as some other R/T owners. I don't understand the sound you hear at 5000rpm. That would kind of concern me. Mine sounds fine all the way to red-line. Since mine is a 2007 model, I don't have a lifetime warranty. The dealership that sold me the vehicle and had done all service work was one that was forced to close by Chrysler. Now I will have to carry it to the Jeep dealer. The warranty may expire before they see it.

I have also had the toot-toot sound since new which is caused by the valve body in the transmission. Since it shifts just fine, I ignore that sound also.

MyGIG lost all the songs I loaded on it about 3 months ago. I treat it as no big deal as I have a 16GB MP3 player anyway. But, you wouldn't have thought that on the day I found everything gone! This past Monday I was treated with the complete loss of the audio control in the radio. Mysteriously, it reset itself about three hours later when I left work for the day and has worked fine since. (I haven't turned it off since either!) It has been 102-103 here every day for a week, so it may have just overheated the amp.

Overall, I am still very please with the vehicle. It is still getting between 17 and 18 mpg in city driving.

Hope you get everything worked out and happy with your ride again soon.

Tim

[rickaren]

Originally Posted by MyBluNITRO

Hey Rick. Mine has had the whistle since new. I now have 30k + miles.
I have pretty much gotten used to the noise. I still can't hear it with the windows up, so I don't think it is as loud as some other R/T owners. I don't understand the sound you hear at 5000rpm. That would kind of concern me. Mine sounds fine all the way to red-line. Since mine is a 2007 model, I don't have a lifetime warranty. The dealership that sold me the vehicle and had done all service work was one that was forced to close by Chrysler. Now I will have to carry it to the Jeep dealer. The warranty may expire before they see it.

I have also had the toot-toot sound since new which is caused by the valve body in the transmission. Since it shifts just fine, I ignore that sound also.

MyGIG lost all the songs I loaded on it about 3 months ago. I treat it as no big deal as I have a 16GB MP3 player anyway. But, you wouldn't have thought that on the day I found everything gone! This past Monday I was treated with the complete loss of the audio control in the radio. Mysteriously, it reset itself about three hours later when I left work for the day and has worked fine since. (I haven't turned it off since either!) It has been 102-103 here every day for a week, so it may have just overheated the amp.

Overall, I am still very please with the vehicle. It is still getting between 17 and 18 mpg in city driving.

Hope you get everything worked out and happy with your ride again soon.

Tim

Hi Tim! THANKS for your reply. Not something that happens here very often for some reason. I am accustom to it anyway with a Home Theater Site I put up back in December 04 and updated again this year, with a total of 52 pictures. That Site has received over 44K "Hits" but never receive questions or comments? (rickaren103's photos and albums on webshots)

Anyway with my Nitro modifications I now want to hear powerful engine noise like in the good-old-days. Sure they were big blocks, but 340's sounded great, too. If anything is wrong with this engine (must be O.K on the top side) I should be covered since I also have the expensive Maximum Care 100,000 7 year coverage plus the lifetime that became part of any Nitro purchase on or after July 26, 2007.

Hell I even bought the Scheduled Maintenance 3,000 mile Care Plus Contract.

I have had no issues with MyGig but have had ALL the upgrades and even bought the new GPS mapping. Since I have only about 9,500 miles on mine after two years it has received really excellent care and I do plan to keep it a very long time.

I really just love this Car/SUV/Truck that is really like a hobby. Never had a car (starting @15) that I did not modify to make it unique. Same here. Really can not justify purchasing it, but sure glad I did.

Happy Nitro Owner

[Frederick]

Interesting thread. I get some sort of humming whistle noise at 2K rpm and above. If I let of the gas it goes away. I hear it with windows up only. Not sure where it comes from though? Inititally I thought perhaps it might be the diff.

[rickaren]

OK I have not found anyone else in any Forum that seems to have the same issue that I do at "High RPM" under full-out acceleration, around 5K RPM and up. I had hoped that eliminating the low speed "Whistling Noise" with the newly designed head gaskets would also solve this issue. Sadly it did not. It appears that the head gaskets only are a cure for a much lower RPM noise. Wife said it is a screaming noise not a whistling noise anyway. With the windows down and radio off, at times when engine is hot it is so loud that you can not even hear the engine! I checked in about Factory Fix on 07s replacing the serpentine belt and tensioner but that addresses a taping noise. No tapping noise here.

Goes back into shop tomorrow to address this issue, plus also the malfunction check engine light came on Monday. I doubt that this is related to the screaming noise, but that would be great, if it is.

Dealership Service Department is very supportive, thus far. I would feel better if I could find someone with the same complaint. Anyway will report back and hopefully this whole issue and any resolve will help others. This is what this thread is all about.

[Frederick]

I changed my oil today to Mobil 1 10-40. Engine sounds sweet and I think the low rev whistling is gone. Took it for a long test drive

[rickaren]

Originally Posted by Frederick

I changed my oil today to Mobil 1 10-40. Engine sounds sweet and I think the low rev whistling is gone. Took it for a long test drive

Let us know how your replacement tensioner works out. My Service Manager ran a check on my serial number today and it did not show any issues to address. Don't think changing my oil to 10W40 will help but if all else fails will have Dealership do it since I have a Maintenance Contract and they change oil & filter every three months regardless of mileage. Hopefully they will find what is making my engine noise and I told them they could keep it as long as they want.

[rickaren]

Originally Posted by Frederick

I changed my oil today to Mobil 1 10-40. Engine sounds sweet and I think the low rev whistling is gone. Took it for a long test drive

Frederick:
If the sound returns, as some have stated in the past, would going to a 10W50 or 20W50 work long term? I raced a drag car years ago and ran a racing oil of 10W50 and never had an issue with the oil. Might be something to consider if indeed you engine noise returns before the next oil change? Good Luck hope just changing the factory oil to Mobil works. Much better than changing head gaskets! However it was covered under warranty.

Interesting Link about using 20W50 engine oils

Shell 20W-50 vs. GTX - Alfa Romeo Bulletin Board & Forums