Worth Replacing Coils w/o Code?

Hey all,

Just bought a 05 DC with 240k on it. I replaced the spark plugs with new Denso plugs and when I pulled the coils out I noticed a couple of the coils had very hard rubber ends and the rubber was cracked.

The truck has no codes and no misfires. I can't seem to find just the rubber ends to replace, so my question is do you think it's worth putting brand new coils in it? I assume these are the OEM original coils, so assume they have 240k on them.

Not sure it's worth the cost at this point or not.

Thanks!

 

Buy oem or find them at the scrap yard

 

I understand to buy OEM, but do you think it's worth investing $80+ a coil if there's no problems other than hard rubber boots on them at this point? This is a 3rd car for me so there's not much driving on it so investing $500 in coils to save a little MPG won't be a sound investment.

 

No, it's absolutely not worth it. Wait for them to fail.

There's also a re-boot kit: https://www.rockauto.com/en/moreinfo.php?pk=4718148&cc=1426935&pt=10150

If you want to get caught up on other stuff: https://www.tundras.com/threads/so-you-wanna-buy-just-bought-a-1st-gen-tundra-eh.115928/

Welcome to the forum.

 

Oh man thanks for that link, I couldn't find OEM ones but that reboot kit will be on my next order for sure!

I read that thread before I even bought the truck..I've been picking away at things the last few weeks. Only thing I wish I would have researched better was 1st gen vs later gen aftermarket support. Finding bed covers, tool boxes, canopies, decked drawer systems and stuff like that is much tougher in a 1st gen without modifications.

Shifty, your posts have been super helpful. I've literally got notes of OEM part numbers from your posts that I've been ordering (already did LBA, filters, diff fluids, tcase fluids, ps pressure line, spark plugs, brake pads, Bilstein 5100's all around) I'm getting ready to do new calipers and CV axles. I'm getting a grinding noise when taking off while turning.

 

"Grinding noise" ... if you have LSD rear-end and you changed the rear end fluid recently, it's probably chatter.

If you (A) did replace the rear diff fluids and (B) you have the sticker saying "LSD" on the back of the rear diff by the fill plug, tell us what you put in the rear diff for fluid, what weight, and was it (unfortunately) synthetic, by chance? If so, there's your problem, you got bit by the same problem as me. Time to purge and replace the rear fluids with Lucas 80w90...

If you didn't change the rear diff fluid recently AND this is a new thing that just started, have you confirmed it's not tire rub on anything?

 

Hi,
I do have an LSD and did change the fluid. I used this Lucas oil https://www.oreillyauto.com/detail/...oil-80w-90-1-gallon/luc0/10046?q=80w-90&pos=1 since the manual said for colder weather to use this weight. I live 1 hour south of Canada in the PNW.

I think the noise is definitely in the front end though. When I got the truck it needed brakes badly. I adjusted the rears and verified they were working properly and I took apart the fronts to inspect them. One of the pistons on the drivers caliper was stuck out compared to the others but I was able to get it back in with a c-clamp. I kept the rotors that were on there along with the calipers and put new pads on for now. I cleaned up all the pins and put new hardware in and bled the brakes. Before doing this job the grinding noise was happening anytime I was taking off slow speed (around 1k rpm like backing out of my driveway and then pulling forward into the street). After the job the straight back and forth taking off was much improved but I noticed that if I was at a stopsign and accelerating while turning from a stop that I'd still have a similar grinding.

I went back underneath and found both front CV boots wet with grease and one side had a new fresh clean ring of grease that was actively slinging grease.

My plan was to get new OEM reman CV's and put some Rockauto calipers ("new") on and see where I stood after that. If noise went away I'd then go back and upgrade the brakes with Z36 pads and rotors.

 

Get you some coil boots and springs from Rockauto.

 

OK, cool. The symptoms as you 1st described them were pretty classic rear-end chatter. Namely: (A) a skipping/slipping/grinding sensation, (B) when moving in fwd/rev at slow speed, with (C) the wheels turned. Like, classic-classic. But you put the right stuff in back there, so ... it's just weird. Some people I've heard describe it as "it feels like ABS is slowly pulsing the brakes, and the brakes are, like, half-grabbing every quarter-second". But the extra info with grinding all the time helps - and is explained by the stuck piston, which could very well be the current cause. I'd consider replacing with OEM 13WL calipers, or just rebuilding your current 13WL calipers, it's not as hard as you'd think. I can kick you a video giving a very explicit detail if it helps (see below), it's really, really not hard! They even give you the rebuild kit p/n you'll need. This should be the exact same caliper on your truck.

What shape are your rotors in? Any signs of grinding on the inside and outside surfaces, or all smooth? Is the e-brake functional? When were the rear brakes adjusted last?

How high did you lift the truck, front and rear? Some grease sling is normal after lifting. If you lifted an inch or more in the rear, I wonder if your LSPV is out of adjustment now and causing early grabbing?

https://www.youtube.com/watch?v=qoQlAW4DPnA​

 

If you had a stuck caliper piston, you need to rebuild or replace that caliper. They won’t stay unstuck once the corrosion has started.

 

And be sure you (1) bleed in the correct order (R-RR, LSPV, L-RR, R-FR, L-FR), if you choose not to use pressurized bleeding like Motiv (2) don't push the pedal to the floor while bleeding and (3) for best results, idle the truck while bleeding. I think this encapsulates the "big 3" path to success.

 

And if you need new coils, Rockauto sells Denso OEM with the name shaved off for a fraction of the price.

 

Rumor I read on the internets - thus grain of salt is required - they come like that because those parts didn't pass quality control, so Denso grinds their name off and sells them to a 3rd party to be re-sold in order to recoup some expense.

 

Do not replace all your coils. Buy one and keep it in the glove box or the under-sear compartment. First bad one I had it was bucking like a bronco and then threw a code so I got one at one of local FLAPS-big mistake. Those are Chinesium and it failed within a couple month. I’ve had good luck with Denso coils from RA. Over time I’ve had 3 fail and 2 develop splits and after replacing 5 one at a time I bought 3 more. I kept the working coils in case I ever have a failure I’ve had absolutely no issues with the new Densos

 

PS - RA Densos are about $50 and be sure to use our discount code

 

Summit Racing pricing is usually about the same as RA, sometimes cheaper, and for the next 30ish hours or so they're giving 10% off and free standard shipping on orders over $109. More info here in case it's interesting for @carlsoncustoms : https://www.tundras.com/threads/summit-racing-10-off-up-to-2-000-expires-8-31-23.129727/

 

That leaves us with the ol’ “proof is in the pudding” equation. I have replaced two over the past 30 months with no problems so far. That’s the only data point I have.

 

I have two replacements in the truck. If I have to replace 2 of them I'll order the other 6.

 

OP - If you’re anywhere near central SC, I’ll give you a coil pack or two

 

I've never rebuilt a multi-piston caliper before, only single piston ones.

Rotors seem ok, ebrake is fully functional. I pulled the rear brakes apart and measured them at 5mm thick and adjusted everything to make sure all the parts moved right. In testing I can stop the truck with just the ebrake. I also adjusted the LSPV up about 3/4" to give it a bit more rear bias.

I didn't lift the rear of the truck at all, just 5100's in the rear and 5100's in the front on the highest (4th?) perch they recommend and factory coils still.

 

Crap, didn't know you had to bleed the LSPV, I only did the four corners. Also what do you mean don't push the pedal to the floor? I just had my wife pump it a few times and the hold it on the last pump and then opened the bleeder and when I did that her foot went down and then I closed the bleeder. It's been over 20 years since I bled brakes so my memory may be foggy on best practices. Also I didn't have the truck running during it. Are you doing that just to get the benefits of the booster?

 

That's a really good idea of just having one on hand ready to swap at a moments notice. I'm going to buy the full reboot kit on RA for now.

There was a guy on CL selling 4 pull offs from a known good '04 Tundra that I wanted to buy but he's not getting back to me. I'll probably buy one OEM to have and then get more as they go bad. I keep a scanner in the glovebox so it should tell me which one is misfiring when it goes bad.

 

Thanks for your generosity, but I think I can't get much further from you.. WA state.

 

You don't "have to" bleed the LSPV. It's just one of those "if you're having issues" or if you know 100% air was introduced into the lines, follow the order: PR, LSPV, DR, PF, DF.

RE: Don't push pedal to the floor. Risk of damage, blowing out seals. If you're not the one pushing the pedal, I'd chock something under the pedal so the person doing the pushing isn't pushing to the floor, too much pressure.

 

So bad news guys, I received the Denso boot kit that Shifty linked. I went to install them all today and when I pulled all coils to do the swap I found about 6 of my coils have a crack along the main body (opposite of the molded line)

I wrapped them in electrical tape for the moment and rebooted them. The truck doesn't throw any misfire codes or any check engine lights at all and seems to run just fine.

What are my realistic options here? Do I absolutely need to replace them all that had cracks or should the tape be ok for awhile until they actually fail?

 

Heat cycling that tape is not the best for the adhesive on it. I think the tape would slough off the coils after a while, but hell it might Bake the tape to the coils, and run another 100k miles.

I'd bet by now the electrical components inside the coils have degraded. Personally, I'd replace all 8 if you could swing it.

Here is the denso Units that you want from RockAuto. Amazon and ebay have WAY too many counterfeits. DO NOT BUY FROM THEM

If you have paypal, you can do a paypal pay in 4 so you'll only pay $110~ish every 2 weeks.

 

I had 2 coil packs with cracks when I changed the spark plugs. I filled the cracks with JB Weld and smoothed it out with my finger. No problems so far. I do have a new Denso Coil pack in glove box and code reader in my truck in the event I have a problem on the road.

 

I’m told those cracks don’t affect function. Not sure about using JB weld but it’s prolly ok. As mentioned by one from the Rock and keep it in the glove box until you get a code.

 

Everyone has cracked bodies in that exact spot. I did also on a few with my 75k mile truck. If you're not misfiring it's not a problem.

I can't say that enough in this thread, so I'll say it again, a little bigger: If you're not misfiring it's not a problem.

 

Thanks for everyone's help, this forum is so much more helpful than the 1st gen Facebook group. I posted the same question about rebooting the coils first there and the admin denied the post and just told me don't be cheap and replace the coils and I'll get better MPG with new coils.