Rattle at idle 2008 5.7 Litre - Secondary air system

Hi folks. I am hoping to tap into the collective experiences here. I am resurrecting a little loved 5.7 Litre Tundra Double Cab Limited edition. Its had a chassis swap at some point but is close to suffering the ravages of the Ontario Winters. This car has been perfect and purred like a kitten. It has no brakes, AC needs a recharge, tons of rust and a stuck 4WD actuator. But other than that its pretty good. I am now trying to fix all the issues and the first was the Secondary air system and valves.

I have installed new pumps and valves and they are working as the error codes have now cleared. In fact I have no error codes showing. However. After installing the Secondary air valves I have managed to get a huge rattle at idle. I retook the inlet manifold off and checked there was no debris in the intakes. All-good nothing to see.

My thoughts is that I have damaged the secondary air pipe coming off the driver side exhaust manifold or stressed the gasket at the 2 bolt joint. The engine now sounds horrendous, but it sounds a little like an exhaust leak, but sounds like a dropped valve. I can't imagine the main manifold has been stressed and broken, but the smaller pipe could certainly be corroded and bent ( similar to the rest of the car). Has anybody got a manifold leak and sounds like the video attached, apologies but the noise sounds even worse on camera. At idle the noise is not great, but at approx 2K revs the noise disappears. I am certainly hoping that the valve train has not decided to die on me, but I will do a cylinder compression test just in case and put a camera into the bores.

More info - Car has been idle for a week ( has been turned over at least once per day). Its on a mild slope. Engine oil looks halfway between marks on dipstick. No pipes disconnected, no cables chewed. No water or oil leaks showing except perhaps the rear cam seal area on drivers side, but its really a very minor leak.

I am a bit disheartened as this was going pretty well until now.

https://youtube.com/shorts/1_q2lFnJBUk?si=O_rBwH1JEEJYgM26

https://youtube.com/shorts/kh7UsnspwZE

 

If it did not have the noise before replacing the air valve and pumps, i can only think of the egr pipes to the air valve breaking or leaking. You can see the lower connection and most of the pipe if you remov the rubber flap down by the rear of the engine. Did you disconnect both sides at the air valve or one at the lower connection? The air pumps only run after sitting for while and then only for about 30 to 45 seconds, so I don't think the noise is from the pumps. There is nothing under the intake to fall in the ports other than the bolts you took lose (excluding any mouse acorns etc.) I don’t see a video in your post.

 

Your video finally loaded (using my phone as a hot spot). It sounds like an exhaust leak to me. Do you have a rubber hose that you can use to move around the exhaust egr pipes to stick up to your ear? Use a mirror to look at the gasket on each side of the air valve.when I replaced mine, the gasket slipped down and only the top bolt was going through the gasket. If you can’t find the leak you can make a smoke tester out of 3 inch pvc pipe, short piece of nichrome wire, tiki torch wick, and baby oil, hook to 12 volt battery for about 45 seconds Hook it up to a vacuum port at about 3 psi and smoke will come out the leak. It costs about 15 bucks in material. You will find all sorts of uses for it afterwards.

 

The fan air pipes are all good. No splits and I replaced the rubber boots to the secondary air valves. I disconnected both sides of the air valve without disconnecting one side on the exhaust... but could be my downfall.
So essentially the exhaust tubes were in place. I can only think , I stressed the drivers side steel pipe and cracked it?

I agree with you, the noise is not from the pumps as it remains well after the EGR system is off. The rattle disappears at higher revs and as the revs drop back down reappears ( leading me to gasket failure, which can sound pretty bad).

The input ports were all taped off well and it was hoovered and cleaned as best I could before the manifold was removed. My second removal of the input manifold showed no signs of contamination. Could a screw have been there already and dropped in the port and worked its way into the cylinder? I hate to think I missed that before first re-assembly and starting up, but certainly could be possible and I have to now get the camera into bank 1 Cylinder 7 and 5 just in case and remove that doubt; I would still be surprised as I would have seen inlet valve damage and I didn't see that, perhaps also firing issues and I have not .
BTW Videos are now linked to youtube ( I couldn't embed from facebook) and yes it sounds like a diesel now. But honestly it revs better than before!

The other thought is that I have accidentally pressed on the injector rail or wiring ( easy done), but once again no engine codes or misfires. It runs great at idle but just has this horrible rattle. Unfortunately I can't get underneath as the rear is jacked for an axle replacement:I could then poke at the heat shields or get a camera up around the transmission to check if this or other things have has been disturbed. I think my next attack is the removal of the drivers side heat shield and better view of the manifold / secondary air connection. This comes with severe risk of rusty bolts snapping!

 

Thanks for the great tip. I did put my camera down around the EGR valve connections. They looked good and no signs of blowout. The tabs were both showing on the secondary air tube flanges, so I am pretty sure they are in place, but I didn't look below and need to do that . They were new Toyota gaskets also, but pretty flimsy . I could also put some foamy washing liquid on the joints to see if they are leaking. But I like your idea. It would then at least locate the leak better . This has given me a bit of hope. Thanks for the conversation; I appreciate you taking the time to respond.

 

Before you go wringing off rusty bolts that may not show you anything, I would first pull the rubber flap down and check the egr pipe from the air valve to the first joint in the egr pipe. The bolts will be rusty and may have started leaking. You can buy that first pipe for about 50 bucks or maybe drill out and replace bolts if the leak is at the joint. Resist the urge to just wring off the rusty bolts and then spends hours trying to remove the stub, in your case i would definitely make the smoker before taking any parts off. There is an how to do vid on youtube and if I can find a picture on my phone of the one I made I will post it. I am on vacation at the moment and can’t take a picture. If you find you have to take rusty bolts off invest in an induction coil heater to heat the nuts and bolts. They are about 200 on Amazon but will save you hours of work, cussing, and even keep you from destroying parts. You will wonder why you did not buy one sooner. If you live in the rust belt, you will find many uses for it. You can heat nuts without dangerous flames. If you can wait until next week, when i get home i will mail you some ni chrome wire, wick, and any other extra parts i have for the smoker. I get home Tuesday. Work on the other problems until then if interested in making one.

 

gypsycatfish that was very wise advice. Many thanks I used a very useful Lysol wipe tube converted to slip onto the stock exhaust. Vacuum was on blow. Didn't need smoke, you can hear the air leaking from the drivers side connection of the exhaust tube going to my new SAIS valve. Still Not quite 100% there as I am still concerned about manifold ( but much less).


I think what has happened is that the original valve was stuck open and there was no build up of pressure at that exhaust joint. With the valve closing it just built pressure and burst an already weak joint

But I clearly now need to try and re-gasket this joint.

I haven't checked stud condition or if the nuts are still there ( actually the top one is there from the latest video). That's tomorrows adventure. Fingers crossed its just an 8 buck gasket fix. The video clearly shows an air leak.... and remember this is not with the engine running, so no wonder its sounded like a diesel! Its a pretty big leak.
https://youtube.com/shorts/p5EkrLOmiqY?si=6Hw8EmyQMA8LVNot

As this is my first 'rust belt' resto ( but not my first resto by far); I am definitely going to invest in an induction coil heater; seems like a life saver here. Many thanks for the offer of the nichrome wire, but I am ok. I do have a human 'vaper' in the family. He can do this for free but really appreciate the very kind gesture.

BTW Canadian prices ( with 30% discount) and +$44 delivery are around $120 (CAD) for the EGR pipe and the two gaskets. That's the cheapest price I have found. Really hoping this is just the gasket.

Once I am back on track with this issue. It's rear bearing replacement and new backing plates, discs and rotors, then the dreaded parking brake rebuild. Transfer case actuator install and then a weld-up/ overhaul of the bed ( "its only a slight perforation" said the original owner.....I joke, but really its the worst I have seen as an example). Enjoy your vacation.

 

A few months ago I replaced the emergency brake cable two to one mechanism under the drivers door. It is a real pain in the butt. The plastic fuel line runs next to it, so no flame allowed. If i remember correctly the nuts are welded on top of the frame and you do not want to twist them loose from the weld. If you do replace with the nuts with serrated flange nuts, and The cable nuts are just as bad.I wanted to reuse the cable from the parking brake pedal so I spent 5he time to free that nut up. I wire brushed what I could and sprayed the threads and let it soak and resprayed. I would start that now to let it soak in for days and respray. I think i bent some old license plates for a heat shield and used the coil induction heater on some of the nuts. A gearwrench box end is helpful working the cable nuts back and forth, i am not sure if cussing helps but I used about as much cussing as I did penetrating oil. I did get it out, but what a heck of a place to locate it. It seems about half way through I thought of a trick that helped but I can’t remember what it was. You will need a mirror on a stick to see where to spray the welded nuts. Too bad that you are not closer, I would loan you my induction heater.

 

A few months ago I replaced the emergency brake cable two to one mechanism under the drivers door. It is a real pain in the butt. The plastic fuel line runs next to it, so no flame allowed. If i remember correctly the nuts are welded on top of the frame and you do not want to twist them loose from the weld. If you do, replace the nuts with serrated flange nuts. The cable nuts are just as bad. I wire brushed what I could and sprayed the threads. I would start that now to let it soak in. I think i bent some old license plates for a heat shield and used the coil induction heater on sme of the nuts. A gearwrench box end is helpful working the cable nuts back and forth, i am not sure if cussing helps but I used about as much cussing as I did penetrating oil. I did get it out but what a heck of a place to locate it. It seems about half way through I thought of a trick that helped but I can’t remember what it was. You will need a mirror on a stick to see where to spray the welded nuts

 

Yes thanks. Just found out that the PB mechanism was jammed solid. Both cables snapped and all the fixings are seized. Previous owner had snapped two bolts off si they need to be drilled and retapped. I will be taking the back box off so this will help gain access. I hear you on the induction heater; that's going to be a worthwhile investment long term. Meanwhile ATF kerosene and acetone are working their way in.