I didnt have a stethoscope, but I heard that you could use a plastic handled screwdriver as a stethoscope, I couldnt hear the squeel, anywhere accessable from the top half of the motor, but buyig a stethoscope is a really good idea, probally really handy in the future.

Unfortunately, the squeeling happened regardless of the clutch being in or out, meaning the trannys ok though at least

Im going to take a closer look at it this weekend, I really hope its the oil pressure regulator or pump. If it has the same symptoms of a spun front bearing, then thats probally what it is. I need to RTV my drainpan anyway, but one thing at a time. Thanks for your info

 

Strain you oil through an automotive paint filter, look for tell tale sparkles.

 

I just changed my oil about 400mi ago so I lucked out there
Also, with my carburator spacer, I removed 1 washer from my oil metering rod (that controls oil flow into the carburater) I just now realized I did not replace that washer, so its probally not mixing oil properly... Although, it used to take at least 1/4 throttle it seems to even move the metering arm at all.... but if theirs no oil on the apex seals, that would explain the squeel *doh* Plus my float levels are set pretty high so the engine doesnt bog in extreme cornering...

 

And you lucked out how? If it is a bearing, changing oil didn't help. A rotary will run for a while without the mop functioning. If the apex seals are squealing on the housings, well.....

 

Check your intake manifold GASKET! It would squeak like when you hold a piece of grass between your thumbs and blow. I discovered it by using a length of fuel line as a stetchescope and bumped into the gasket. The squeak changed a bit as the gasket was pushed/pulled.

If you've eliminated all the potential noise makers under the hood and a rebuild is looming in the forefront of your mind (thanks to all the wonderful advice you've been given thus far j/k), poke around your intake manifold for a while and see/listen.

 

You did a pretty good job eliminating options, and though some guys missed it, the fact that you ran your car for a second or two without the belts says it's not an alternator or water pump problem.

And since it does the sound at idle without the clutch engaged, you know it's not a transmission or drivetrain problem.

So the only thing that leaves is the engine and the intake. Now I haven't heard this squealing that Jeff20B speaks of, but hey, since it's either intake or rebuild start with the cheaper one. Get a new intake manifold gasket and see what you can find.

One thing I learned though, if you take your intake manifold off, you should have a drill with a brass wirebrush and a big ol' can of gasket remover.. as well as a couple of days. My 22yr old gasket was so thick and caked on there that it took me FOREVER to get the damn thing off... by spraying it with gasket remover and hitting it with the wirebrush until I saw metal everywhere (though the old gasket looked like metal at first to me).

Then soak your new intake manifold gasket in oil. That'll cause any little air holes to be filled with oil, and create sort-of a microscopic spunge-like effect, helping the seal between the gasket and the manifold/engine.

If that doesn't fix it... rebuild the damn thing!

Jon

 

Thanks! that is a really good idea, and its so simple, who would have ever thought of that? Its just one of those things like, it cant be that easy, it HAS to be something else, these are RX7s after all hahha.

I just got through browsing section 2 of the shop manual (lubrication) and the shop manual calls for 0~1.0mm (0.040") clearance between the metering oil pump lever and washer (which lifts it)

When I installed my Holley according to Racing Beat instructions, it said that the clearance should be 1/4" +or- 1/32" There isnt much, but there is still some discrempancy. Even if it is just a couple of cc's over a few minutes differance, that could probally add up to a lot over 400 miles.

Failing the intake manifold gasget inspection, I had a pretty good idea. Im going to pour about a capful of oil down (perhaps each) intake port, and if the squeeling vanquishes, then thatll tell if the apex seals are being noisy, also on what rotor if its just one

I am most definately going to tighten my metering lever to washer clearance. cause at 7500rpm you need as much lube as you can get. I should lower my floats to proper level, for adequite oil/fuel mixture.

I just hate to think how much damage unlubed apex seals could do. This wont explain the oil problem in the first place (if there is one) but its a good lead on where to go

 

In reference to the couple posts I didnt see

I meant I lucked out that I changed my oil right before the symptoms started. If I already had 2500 to 3k miles on it, itd be shiny black no matter what. But if its already black or chunky at 400 miles then theres definately metal scraping metal issues. I flushed about a quart then also, it wasnt coming out brand new looking, but it was close.

I put a brand new intake man. gasget on about 6000? miles ago, or so, with the new manifold. I torqued it to I think 20lb-ft becuse the manifold is aluminum. Which isnt very much considering, and maybe hard driving worked it a little loose

 

Vipernicus, I'd have to recommend against soaking the gasket in oil prior to installation. The gasket I mentioned in my previous post was on a fresh rebuild in an RX-4 not two days old when it started to leak. The very topmost part of the intermediate ports was where the air was entering/escaping past the gasket. When I pulled the manifold, there was a generous amount of oil covering both sides of the gasket around each port (especially the secondaries as they had not been opened yet).

Luckily since the gasket was so fresh, I was able to clean it carefully with brake cleaner, along with the manifold and engine. I then used RTV and gooped around each port hole on both sides of the gasket, being careful to apply a liberal amount around the top of the intermediate port holes (liberal here means only a slight bead oozed out once tightened).

Two days have elapsed and there have been no further leaks.

It's my guess the first carb, which caused the header to glow, warped the intake manifold slightly from all the ambient heat. What's more, the GSL-SE rotor housings we used with the RX-4 side plates, which lack a coolant port by the way, allowed the heat to build inside the manifold instead of being taken away as would have happened had we used earlier rotor housings with coolant passages.

I've since changed carbs and added a heat shield. The headers no longer glow and it runs a lot better. No need for coolant inside the manifold as long as the fuel delivery is tuned correctly.

 

you should drain all of your oil and run a magnet threw it see if theres metal shavings on it...
really sounds like a posibly spun bearing to me, especially if your oil pressure droped at the same time...


and ive seen cars run with no OMP and no premix and they never made any high pitch squeeling.

 

Your not going to beleive this!!

I tried pouring some oil down the carb to see if that would help or rule out the apex seals. It started up after sitting for 3 days WITH the squeel.

I poured down a couple capfuls of oil, nothing. I though 'Theres just not enough oil' so I turned the car off, opened the throttle, poured it down just right out of the bottle, started it up STILL SQUEELING! So with it running I poured more liberally (meaning about a 1/4 quart in all) The squeeling didnt stop but GODDAMN thats toxic!! That was almost as bad as a nitro methane leak at the NHRA races! Eyes watering, lungs burning, and a HUGE smoke cloud coming out the tail pipe I hope that didnt do any reproductive harm!

Although pouring oil down the carb is a good way to find leaks I discovered, smoke started coming out a few of the gasgets close to the front cover and a large cloud from the header (1 exhaust bolt is almost completely stripped; holds maybe 2lb ft, and the other is broken off in the housing)

The intake manifold gasget didnt change pitch no matter what... IT WAS THE CARB TO MANIFOLD GASGET SQUEELING!! The squeeling stopped, but the symptoms still persist OR a new set of problems...

 

Vacuum leaks can squeal like a pig.
As for the lack of oil pressure at intermittent times, prolly just a flakey sending unit. Best thing to do, is hook up a mechanical guage, and let it tell you the real truth about what the oil pressure is doing.
A mechanical guage can easily be hooked up by drilling/tapping the banjo bolt at the rear oil line fitting. This works with either a front mount oil cooler, or the beehive. Of course, with a beehive, you can also drill/tap the block-off bolt at the bottom, where the oil line attaches with a front mount cooler.

 

NEW/REMAINING PROBLEMS

Issues:
Poor idle
Running hot (on the top end of normal operatering range)
Glowing red header
Shotgun blast of a backfire 10secs after turning off

Should this be a new post?

Story:

I put my 1" carb spacer back on, so I figured it would run like it did. Used to idle relatively smoothly at 800rpm

Now it doesnt really want to stay running below 1500rpm. I figure this part is to do with an intake leak (reused carb gasgets, and one carb to manifold bolt spun) and perhaps the exhaust leak isnt helping. Thats ok with me for now.

I then noticed though that my exhaust header was turning red! Well, I never have seen that happen before.
I never watched it over 1500 rpm for any length of time either. I thought perhaps thats just a characteristic of 1/8"to 1/4" thick stainless steel.
It cooled to the touch less than 5 min later I found by accident. (Car being off for 5 min)

However that just didnt seem right, well I run a little advanced, and heard it can turn manifolds red advancing over 5 degrees. So I put leading and trailing right back to the mark. Still red!

I retarded the distrubiter a bit, and that didnt really halp much, so now its smack dab in the middle. (Straight up from when I timed it with a light)

I cannot get it to idle like it did at 800, no matter how rich or lean or fast idle adjust. 1500 is the lowest smooth idle it will go. It idles quite rough at 800, the fluctuates down to like 400 then dies

I looked at the plugs, they were the reccommended Autolite kind, pretty black, with little spots of carbon

SOLUTION:
I think I have multiple things happening here at once. High / poor Idle due to intake and perhaps exhaust leaks. The backfire, because of quite hot exhaust gasses combusting.
Why its running so hot? Not sure. I would thing a coolant issue still, maybe needs a new thermostat again. Red Header? I really dont know with proper timing, maybe thats normal for an SDJ? Is it with RB? I would not think so. Ill do a search soon. I dont want to think its forign material

How can a carb cause a header to turn red? Wouldnt the rotor housings ambient heat have caused it to warp? Can I use the same carb and still fix it? Would 92 octane help? Ive got 89 right now.

Ok enough for now! All advise appriciated!

 

your vacuum leak is causing the fuel mix to run lean due to the unmetered air. This causes a high idle and glowing header. Toss the Autolites and get a set of NGKs or Nippon Densos.

 

Like I said before, thats just too easy of a solution to be right Hahahha! New plugs and gaskets it is! Time to drill out that bolt, and get some oversized ones. Hopefully that fixes most the issues! Thanks man.

 

I put a new gasket between the carb and manifold, and now it will idle nicely at 400 rpm!! So everything must be pretty sound I perfer it at 800 to 1000 though (Better for launching).

You were exactly right Trochoid. No red header, temperature back to normal, car running nicely now. Thanks!!

 

So it was the gasket. Hurray!

 

YAY FOR NOT NEEDING a REBUILD!!!!!!!!

oh, but why wouldnt you have oil pressure?? duh duh duh.

 

The gauge is most likely out and I must be getting oil pressure. Ive put on about 600mi since my last post, and its still running just fine (except for the oversized exhaust bolt that stripped out of the block, even JB Weld is having a hard time keeping it in. But this is a whole nother story. Solution? More JB Weld!)

 

This post helped me out definitely. I need a carb intake gasket. My idle stays at 1500 rpms too. Car runs great except for that issue. Thank you Slayerx7.

 

You can remove the exhust studs with a stud puller. After you get it off if yu need 1 just let me know i ll remove a stud off one of my junk housings and send it to you. Good luck and glad to hear you didnt need a rebuild.

 

Don't usr a stud puller, it will tear up the threads even more. J B Weld will not tolerate the heat, it softens with high heat. Remove the stud, use either a helicoil or re-tap fo the next larger metric size.

 

 

Yeah, I have seen first-hand that JBWeld will melt right off with the heat of the rotary exhaust.

Jon

 

Hey Im glad this thread helped someone else

Also the JB Weld package says Itll tolerate upto 3000Degrees I think it was. and like 6000PSI

Well, I decided to drill out the broken bolt, and put a new stud in and thats holding fine

Now the Stripped bolt seems to be the problem. I drilled the housing out just enough so the 7/16 Oversize plug would thread in tightly. I didnt even get down the street before it fell out

Went back, bought another WITH A LOCK WASHER. Unfortunately, that ended up stripping out on the final torque - I felt like

I JB welded it a little.

Then put in a lot more and let it sit for about 30 hours; it held for about 3 days.

Helicoil may be the only way to go, perhaps I can add even more JB Weld or try different mixing ratios, before finally breaking down and buying the $76 helicoil kit