2001 Max Engine Rumble at low RPM
 

So I just picked up an 01 with only 120K on it after a previous car deal fell through and i thought I won the lottery. Ive seen people who have over 200K on these cars so i thought I picked up a great deal. The body, paint and interior are damn near mint condition so when i test drove it the rumble I heard i passed off as an exhaust leak and figured for 1600 bucks i can live with it. When I found out the car was from NJ, the rust belt, i looked under the car and the floor pans had zero rust on them and there was no sign of rust on the frame. As i was changing a locked up rear locked up caliper, which was a breeze by the way, i went to jack the front up to bleed the front brakes and saw the rust out lower radiator support. I ceased my efforts of jacking the front up because i didnt want to add excess strain to the lower tie bar seeing as how its still in one piece. I have the radiator support on order and plan on changing that this weekend. I then got to thinking, could the rumble be coming from the engine rocking on the firewall? With the wealth of knowledge on here, can that rusted out lower support allow enough movement with the mounts to rock the engine that much? I am planning on buy a new set of engine mounts, ive read the set on ebay for under $100 is actually a decent set. Once i get this and a stupid passenger side water leak fixed I will finally be happy with this car. Any and all help would be greatly appreciated.

Depending on your meaning of rumbling, it absolutely could be the rad support. If you have an automatic you might want to grab engine mounts for a manual as they are not self adjusting. They may make it less smooth during acceleration but they can't go bad and fry the ECU.

By rumble i mean it almost sounds like an exhaust leak, well then it made more sense that something could be rubbing on a mount or firewall. Ive had 3 other dudes who were ASE certified prior to joining the Marine Corps who cant pin point it. That and the stupid passenger water leak is enough to drivea sane person mad. I have already disconnected the electronic mounts and plan on replacing with MT mounts.

Depending on how bad the lower radiator support has rusted out, the engine is not sitting in the proper position. There could be pieces rubbing or maybe it is an exhaust leak. Check the exhaust y-pipe where the pipes from the 2 engine banks come together just before the main catalytic converter. Nissan used a woven flexible material at that junction and it will rot out.

Checked the Y pipe and its leak free. Heavy acceleration in a turn, right or left, and its not present. Its super annoying and i hate driving the POS when i know its something that can be fixed, just have to find the source .

Does anyone have any experience with the Anchor engine mounts sold by Rockauto?

Yes. Very good - I have replaced my passenger-side AT 2000 mount with an MT mount and I can't complain. Inexpensive, and it has worked very well so far.

Did you use the inserts that came with the Anchor mount or did you spend the extra on the energy suspension inserts? Thanks for well needed input.

I kept the original (Anchor) inserts.

Although I have nothing to offer in regards to your issue, but feel that $1600 for 01 with low miles is a steal

Does it rumble all the time? If it is intermittent check the radiator fans - if the their bearings are worn when they are on they will cause a rumble that you can feel through the car/steering wheel.