High pitched wine from under car - possibly transmission

(Vans) #1

1988 XJS coupe V12. When first starting out I get a high pitched wine that changes with speed. It goes away after warmed up. Transmission fluid level is good. Any thoughts ?

(Greg) #2

When is the last time you changed the fluid and filter? I haven’t changed my 88 XJS ATF yet (still getting engine going), but I put in Valvoline MAXLIFE Synthetic ATF into used cars I have bought, and they shift and work great, and are still going strong at 195,000 and 175,000 miles.

Another thing I do on my used car engines and transmissions, is I use AutoRX (look it up, non-solvent cleaner). I swear it works. Those two cars with 195K and 175K also have great engine compression.

(phillip keeter) #3

Does it wine only in gear? If no, have you started engine and then got out and listened in trunk? Maybe the fuel pump?

(motorcarman) #4

My 1988 Chevy C2500 has a gearbox ‘whine’ at start-up sometimes.
Probably a GM 3L80 thing.


(Roderick) #5

VANS, Not sure from where the sound is coming from… although you say it comes from under the car, sometimes when the fan belt is loose, it will whine and change with acceleration. Also, it could be coming from where the fan belt contacts the gear assemblies of the power-steering, water pump or alternator. These sounds can appear like they’re coming from under the car when you’re driving. Diagnosing is fairly easy if you want to rule this out. Good luck!

(Robert King) #6

Same noise in my ‘88 XJS, it was there last spring but disappeared during the warmer months. Now that temps are colder, it is back. Seems more load related, may be fuel pump or regulator. Doesn’t seem to be affecting anything.

(Kirbert - author of the Book, former owner of an '83 XJ-S H.E.) #7

Many have reported whines that apparently come from the cooling circuit, although it’s not altogether clear how it makes sound; perhaps it’s something about the air purge piping. The recommended mod of installing a flushing tee at the high point in a heater hose and using it to properly fill the coolant circuit sometimes seems to clear up the whine.

(Greg) #8

is it a high-pitched whine or wine? you may just need a corkscrew.

(Robert King) #9

It is a hydraulic noise, not rpm related, and fairly high pitched. It could be cooling system, but changes in engine rpm do not affect it. That’s why I am thinking fuel pump or pressure regulator. It seems more toward front, not from boot. I just changed coolant and thermostats with no change in noise; have good heat and no temp gauge fluctuations, so not an air pocket in my opinion.

(Robert King) #10

By the way, I wish to thank Kirby for his excellent reference and his expertise on the XJ-S. His book has helped me sort my Cat, and so many others.

(Robert King) #11

Been consuming more wine since acquiring my XJ-S, coincidence? I think not…

(Paul M. Novak) #12

I am surprised that Dave the Limey hasn’t responded yet. I believe that he has the same noise on his XJ-SC and did a fair amount of detective work tracking it down to the transmission. He posted about this a while ago, maybe a year ago. His posts should be in the archives.


(Mark Lee (Pay Pal Patron)) #13

XJ-S’s have a turbohydro 400 transmission with a Jaguar Specific Something something diaphram. Crap! I hat it when words slip out of my head and onto the floor rather than through my finders and onto the post. It make me look like such an idiot.

The TH-400 does or can have a very slight whine especially in reverse or from a dead stop into 2nd gear. this usually clears up with a fluid and filter change. But it’s not uncommon. The caveat to the oil and filter change is My 70 Camaro RS/SS has had the whine ever since I can remember - I’m not that old! It was my parents car. Mum bought it new. SHIFT MODULATOR, Diaphragm. HAH! I remembered!

It’s really hard for me to say without actually hearing it. because it could be nothing or it could be serious.

How’s that for a useless post

(larry2236) #14

Here’s what I did. Take the spare tire out, crawl in the trunk with your auto stethoscope, find a hole to stick it through until it contacts the diff. Have someone drive you around while listening to the diff . Pretty unorthodox but it will fine or eliminate the diff. Jag diff’s are very pron to whine

(motorcarman) #15

30 years ago I worked at a repair shop that was 2 blocks from the dealer. A cop showed up one day and asked if anyone was driving a car or saw someone driving a car with the following description (he described the car). We told him no and why was he asking??

He said some lady was driving in the area and saw a guy stop the car and then opened the trunk. There was another guy in the trunk and then the driver slammed the trunk lid closed and drove away.

I called a few buddies at the dealer and they said “Yea, the cop showed up here and inquired. We were checking for noises in the back of the car”.

I guess the lady thought someone was KIDNAPPED!!!