Okay guys, so the other night I was about to change my oil and oil filter because I hadn't done it in about 4K-5K miles so I decided to do it. I put a K&N oil filter on with 5 quarts of 5W-30 Mobil 1 Extended Performance and 16 oz. of NoLeak Engine Oil Treatment because I have rear main seal leak and decided to see if that would work. Before I did the oil change, I ran a half can of Seafoam through the brake booster line and I put the other half can of Seafoam in my oil crankcase the day before and drove the car a little over a 100 miles to get the Seafoam to circulate throughout the oil in the motor to clean any kind of sludge or carbon build-up in there. Now I know Seafoam REALLY thins the hell out of any kind of motor oil so that is the other reason why I wanted to change my oil/filter. So anyway, I drained the oil pan and changed the oil filter, put the new filter on and new oil in and started the car. Ever since I did this, my car has started making a high pitch screeching noise when I start the car. It sounds almost like a wet belt screeching or something. I was just wondering if anyone had any inputs on this and what they think it could be?

 

Did you degrease the engine or anything? Sounds like a belt or separated balancer to me.

 

Spray your belts with belt dressing. Could need to tension your alternator belt.

Problem will be fixed.

 

you probably shouldnt have drove with seafoam in the motor your really only suppose to let it idle for a few mins. ive personally seen someone throw a rod threw an ls1 doing this lol. as for the squeak typically nothing serious squeaks so hopefully you will be ok. if its not the belt just try to locate more where the sound is coming from and let us know

 

Well, when I turned my car back on after changing the oil, I was revving it up to make all the smoke come out of the exhaust because I put half of the Seafoam can in my brake booster line. While I was revving it up, it made the screeching noise I explained above. I just so happened to be already taking a video of the smoke coming from my exhaust and the noise is on the video. I will have to post it up so you guys can hear it.

 

wow 100 miles with seafoam in the oil. might have gone a wee bit overboard.
you may want to take a look at your rear main seal again and make sure its not leaking worse.
you could also try flushing the whole system with new oil.

 

You guys keeping adding thinning agents to your oil.....Bring it by the shop afterwards and I'll be happy to swap in another engine for ya.

 

If it sounds like a belt screeching it's probably a belt screeching... Like I said before, spray on some belt dresser, you probably got some seafoam on one of your belts.

 

I don't add thinning agents, but I do tend to add too much boost which gives similar results.

 

I only drove 4-5 miles when i seafoamed, 1/3 in gas/oil/brake booster

 

Yeah but I've seen on other forums where people say to drive 100-200 miles with Seafoam in the oil and then change it. I guess it depends on the car and people's opinions but I do remember seeing people say that though. I am definitely going to change the oil again soon to make sure all of the Seafoam is out of there. I was going to change my spark plugs soon too.

 

Yeah I think I might have because I did spill a little bit when pouring it in the brake booster line. I am just trying to think what kind of belt is around the brake booster line? I'll have to look tomorrow.

 

I had a similar prob, but i seafoamed the injectors and now i hear a clicking sound. before it was good now.... i dont like the sound of it.

 

Yeah I don't think I am going to be using Seafoam in my oil ever again, or any other oil additives for that matter. I may just stick with putting the Seafoam in the brake booster line only, since I've never had any problems with doing that. This was the first time I put the Seafoam in my oil and I must say I won't ever do it again lol. I hope the screeching noise goes away on its own, hopefully I just spilled some Seafoam or oil on my car somewhere under the hood onto something that is making that noise. It seems like it only makes the noise when the car hasn't been warmed up yet. It does it the most on a cold start, (i.e. when the car has been sitting for hours or overnight and hasn't been driven for awhile.) And that NoLeak engine oil treatment stuff I put in my car doesn't work either. It's junk. My car still leaks oil the same way it did before even using it. I am about to contact the company for a full refund because they guarantee it works or else you get your money back.

 

you should change your plugs immediately and flush your oil.
noises come and go, could also be a combo with the weather.
just try not to make it worse. if you had a 300 i would just change the belt out (cause it takes like 10 minutes) but im not sure how difficult it is on the 400, but might not be a bad idea.