Lexilux

Hi all! New to CL and new owner of a 99 GS400. I just had both motor mounts replaced....they were in pieces and now I am feeling a "rumble" under my seat. Before I had the mounts replaced I didn't feel any vibration...I just noticed that when I took off from a complete stop and had to accelerate a bit harder she felt like she wasn't getting enough gas or shifting sketchy. In fact, I found myself looking at the gauges because she idled SO smoothly! Anyway, mechanic determined motor mounts were bad and I asked him about the transmission mount. He said it looked good so we didn't replace it as I was tight on cash Now I feel this rumble..pause....rumble....not sure how to describe it better and I hear a droning noise too. Droning is faster when in park but slows down when I put her in D, N or R? It wasn't there when I brought her in and I have no idea what it is. I hate it when I take a car in for a fix and it comes back with a DIFFERENT problem! 165k on the odometer. Frustrated....Thoughts please.....

PS....I am a woman and while I trust my mechanic (also a Lexus owner)...I'd like some input before I take her back to him. Thanks!

ttaylor993

No advise on your issue; just wanted to welcome you to the club!

Lexilux

Thank you! Glad to be here Been reading for days and gathering some great tips from all the other CL members.

repugnante

Tranny mount. Just because they "look" good doesn't mean that they are good. Replace then check back....

Lexilux

Thanks....already working on that but I don't think the noise I'm hearing is from that. I am also hearing something that "sounds like" a fuel pump priming after I come to a stop.... I'm wondering if they pulled something loose or broke something when they replaced the motor mounts? Thanks for your input!

porn-adkt

iTrader: (37)

Thats your Brake Master.. You are all over the place with trying to diagnose the issue, take it to a repeatable mechanic to diagnose or the Dealership. Once diagnosed figure out if you want to pay for it or do it your self.
Other than that It is Very hard to Diagnose a sound over the internet, especially something that may not be common.

Lexilux

Thanks for your input. After googling all afternoon I figured out that is what that "priming" noise probably is and I NEVER heard it before the car went in for the motor mounts. I'm not looking for anyone to "diagnose" over the internet...I was looking for input so that I am not completely in the dark when I take the car in for the transmission mount tomorrow. I have had this car for 1 week and have had to unexpectedly spend $600 on mounts. I won't be fixing it myself.. .I have to pay someone else to do it so I came here looking for ideas...not diagnoses and wondering if they damaged something when fixing the mounts. Isn't that part of the reason for this forum?

So is it normal to hear the master cylinder prime? I guess it's possible that I didn't notice it before....

Thanks again

Lexilux

Had the tranny mount replaced yesterday and still have the rumble. Mechanic says he doesn't know what it is and he thinks it idles great but it is not super smooth like it was when I brought it in to have the front mounts done. I had zero vibration prior to replacement and he says the motor was still sitting on rubber although compressed and crumbled. He encouraged me to take it to Lexus and see what they say if I was still concerned about it and let him know if it got worse. He said that it may have been there before but was masked by the fact that the motor wasn't being held down firmly because the mounts were trashed and that a bit of settling may occur after a while. While it seems like a reasonable answer, my searches here and on the internet in general come up with OEM mounts should make things smoother or they may have been improperly installed? Since the mounts were broken when I bought the car (I didn't know) I have no idea how it was prior or how long the mounts were broken. Is his explanation to me reasonable? Thanks!