Car sounds like a lawn mower!

[SlidnSideways]

I just installed a hotshot header onto my 89 240sx and started it up without anything plugged into the AIV hole. My car sounds like a lawn mower and when i step on the gas it sounds like there may be a metal rattling noise comming from the header.

I just got my head repaired and put it back on my car and its missing 2 of the studs for the exhaust header which i guess could maybe be the metal rattling noise???

Would that unplugged hole in the header be the cause of the lawn mower-ish sound as well as the rattle type of noise?

Any help is appreciated

--Tim--

[s13sr20chris]

yes and yes.exhaust leaks frequently sound like knocking.

[benemorius]

hah. If you think it sounds bad now, try taking it out for a spin. Once the engine gets loaded the noise gets LOUD. I drove around like that for a bit while looking for a bolt to plug the hole. In the end, I learned about the '$.05 mod.' I dunno if you've heard of it, but it's the greatest thing since sliced bread. Just rip off the end of the aiv pipe, place a nickel in it, and screw it into the manifold. Or.... maybe nickel is for egr and it's a quarter that fits the aiv... well I forget. You get the idea, though. Just throw some money at it until the problem goes away.

EDIT: of course, this is assuming that you don't want to put the aiv back on, but I can't imagine why you'd want to do that.

[SlidnSideways]

yea i heard of the nickle plug solution. I actually found out that the EGR and AIV are same size and since i couldnt find a plug anywhere AT ALL and needed something to plug it from the AIV being practically welded to the old header i ordered a new EGR from the dealership.

I couldnt get my EGR hooked up thinking there may have been a problem with it but just got it hooked up yesterday. Yea im waiting on my new EGR pipe so i can cut it and block it with a nickle, dime, penny, silver dollar....Anything it takes at this point! heh

So you guys are saying that once i plug the AIV it should take away both the lawn mowerish noise and the rattle type of noise too?

THANKYOU for all of your help! Thats a big weight off of my shoulders!

--Tim--

[NISTECH]

A bulk of the noise will go away, however with the broken/missing header to head bolts you will still have a leak. not to mention your header will likely warp.

[SlidnSideways]

Really? Even with just missing one stud on each side?

They broke off about a centimeter inside of the head so im not sure how to get them off and would hate to pull the head again?

Is this a major problem?

--Tim--

[NISTECH]

You dont need to pull the head to get them out. You remove your header and gasket. clean the area around the broken studs with carb clean. Use a drill to drill directly into the center of the bolt. not to big like an 1/8 inch bit will do. then use an ease out to remove the broken stud. Do not drill too deep or you will hit a water jacket. That would be really bad news. Once you extract the broken stud ,install a new one. You must be precise when doing this, make sure you drill straight into the center of the broken stud. This will give you your best chance of getting it out easily.

Now you ask if this is a major problem, that depends . When your new header warps and the exhaust leak becomes very similar to the lawn mower sound you got know ,are you preparred to go out and buy another header?

[nizmo569]

If you need to plug the holes on your header nissan sells a egr plug.

[SlidnSideways]

Where is this EGR plug?

I have been searching for something to plug it with for around a month and a half. Ive gone to Lowes and bought a few plugs from the plumbing section and one size was just barely off. I tried a hardware store and they also had the same size that was barely too big but the next size down was way too small. i called a nissan dealer and they said all they can get is the tube.

For now i have the tube ordered and it should be here on the 24th but its gonna cost me $50 and if i can find a plug for cheaper i would love to.

I even tried a junk yard but i went today and they had not one damn 240 there. Found a stanza but couldnt get the damn thing off.

Any suggestions?

--Tim--

[NISTECH]

Get the plug for a 2000 or 2001 xterra's manifold that does not have EGR. Some had egr and some didnt. It didnt depend on wether it was california or not it was just some didnt have it.

[SlidnSideways]

Ok well what about an idle problem? I drove the car about 300 miles with the regular header on it and the EGR wasnt on all the way (i thought it was but it rattled loose on the way) and the idle was weird.

The car would idle regularly at around 1500. After driving it a bit it would slowly raise itself when i was at a stop till around 2200. With the new header on and the EGR hole wide open it idled at around 2000 regular but after driving alittle it got up alittle higher and then started revving itself. It would fluctuate between like 1800 to 2500 in like 3 second intervals.

Could this also be the open hole or does this sound like something like the idle air control valve? We didnt put a gasket on the intake manifold when we first put it together and blew coolant threw the intake so maybe that threw off the idle air control valve?

THANX AGAIN!

--Tim--

[NISTECH]

Check your tps adjustment, sounds like it is out. Try a search for the setting procedure. Its been posted many times should be fairly easy to find.

[SlidnSideways]

Ive searched a bit and am alittle bit confused...I will continue my search but figured i would post what i was confused about.

I read somewhere that if i adjust the idle with the screw behind the intake while the tps is disconnected to about 650 then connect it that it will be at about 700 firm.

I read somewhere else ( or maybe misread ) that the above thing isnt done anymore and that you have to remove a screw from the tps harness and move it around until the car jumps? I dont really understand this method.

Does anybody know what im talking about? Which should i do?

--Tim--

[NISTECH]

The first one is to adjust base idle. The second one is the one your after but lacks important info. You LOOSEN not remove the 2 screws holding the TPS to the throttle body so you can rotate it to obtain .45 to .50 volts on the center wire of the tps. This would be the gray pigtail connector coming out of the TPS.

[NISTECH]

oh yea , while it is plugged in. you back probe the connector.

[SlidnSideways]

Ok i think i got it now. Thankyou for all of your help. As soon as i can plug the hole in my header ill try the tps thing if it still idles funny.

After searching for a bit i found that all of my idle problems were common with other people who fixed their tps and the problems went away so im feeling optimistic for the 320857 time in 6 months of rebuilding this engine!

If i have any further problems ill be sure to post but thanx to everyone for your help! Especially NISTECH! Your speedy responses and broken down answers made things sooo much easier!

THANKYOU!

--Tim--