99 Tahoe ticking

[biznazion]

I've got a 99 tahoe with 155K on the odometer. Last winter it started ticking when started. It seemed connected with cold[er] weather and would stop shortly after the truck warmed up. The truck has had the intake manifold resealed twice and it's leaking again from the front left corner. I read some posts about "piston slap" and thought maybe that was it, but the truck still does it in warmer weather. It seems to be totally random and doesn't matter if the truck is fully warmed up or not. Sometimes it will tick for a few seconds, sometimes it will last for 15 minutes or more. The ticking frequency will increase with engine RPM and seems to "fade" away when it stops. Sometimes just shutting off the truck and restarting it will stop the noise. There doesn't seem to be any effect other than the noise - which is annoying.

[j cAT]

Originally Posted by biznazion

I've got a 99 tahoe with 155K on the odometer. Last winter it started ticking when started. It seemed connected with cold[er] weather and would stop shortly after the truck warmed up. The truck has had the intake manifold resealed twice and it's leaking again from the front left corner. I read some posts about "piston slap" and thought maybe that was it, but the truck still does it in warmer weather. It seems to be totally random and doesn't matter if the truck is fully warmed up or not. Sometimes it will tick for a few seconds, sometimes it will last for 15 minutes or more. The ticking frequency will increase with engine RPM and seems to "fade" away when it stops. Sometimes just shutting off the truck and restarting it will stop the noise. There doesn't seem to be any effect other than the noise - which is annoying.

ticking is the lifters. these engine run better on 100% synthetic oil. thats what I have been using since 2000 on my 2000 5.3L silverado. when new I had these issues.

the mobil 1 synthetic oil now is dexos GM approved and I have found this oil has additives to keep the engine clean and quiet.

with your problem I would add only 5-6 OZ of marvel mystery oil to you engine oil. now if the problem goes away this means the oil your using is not doing the job or perhaps cheap oil filters.

so if the problem is corrected change oil with the mobil 1 use wix / purolator pure one , or NAPA gold. these filters are of a high quality and work best. do not use those FRAM fillters. they allow larger particles to pass,

[j cAT]

Originally Posted by biznazion

I've got a 99 tahoe with 155K on the odometer. Last winter it started ticking when started. It seemed connected with cold[er] weather and would stop shortly after the truck warmed up. The truck has had the intake manifold resealed twice and it's leaking again from the front left corner. I read some posts about "piston slap" and thought maybe that was it, but the truck still does it in warmer weather. It seems to be totally random and doesn't matter if the truck is fully warmed up or not. Sometimes it will tick for a few seconds, sometimes it will last for 15 minutes or more. The ticking frequency will increase with engine RPM and seems to "fade" away when it stops. Sometimes just shutting off the truck and restarting it will stop the noise. There doesn't seem to be any effect other than the noise - which is annoying.

so did you get anywhere with this lifter noise ?

[biznazion]

I have been using castrol GTX oil and carquest filters (which they tell me are made by wix). I put in a few ounces of Marvel Mystery oil a couple days ago and it has ticked a couple times for a short period. Yesterday I don't think it ticked at all. I need to change the oil again - so perhaps I'll try the synthetic route and see if that helps also.

[j cAT]

Originally Posted by biznazion

I have been using castrol GTX oil and carquest filters (which they tell me are made by wix). I put in a few ounces of Marvel Mystery oil a couple days ago and it has ticked a couple times for a short period. Yesterday I don't think it ticked at all. I need to change the oil again - so perhaps I'll try the synthetic route and see if that helps also.

that use of dino oil may be the problem. I have used dino oil on the older 15 year old GM engines with no problems. with the new engines things are quite different. these engines are picky on spark plugs and engine oil.

now with synthetic I go about 7-8,000 miles on the oil changes. twice as much as I did when on those older vehicles. but I replace the oil filters at the 3500mile point.

the castrol filters if they are wix is good.

the 8000miles is what some say a waste of synthetic oil. they go up to 15,000miles on the oil changes with these engines.

marvel mystery oil is a great product to reduce corrosion, lubricate the fuel system fuel pump etc. reduce engine carbon deposits which cause lifter noises.

this product as you have used a few ounces to the crankcase oil SLOWLY removes these engine deposits which the filter can handle and not do damage as other solvent type additives will do.

I also add a few ounces to the fuel to keep the injectors lubed and clean. very smooth idle .

good luck / cheap fix .

I forgot to say always change the oil when hot !

[biznazion]

I changed the oil last weekend with Mobile1 5w-30 for older engines and a wix filter - still have ticking on about 50% of the startups. Seems more inclined to tick when already warmed up.

[j cAT]

Originally Posted by biznazion

I changed the oil last weekend with Mobile1 5w-30 for older engines and a wix filter - still have ticking on about 50% of the startups. Seems more inclined to tick when already warmed up.

you may have some carbon in the lifters. this will cause them to leak down over the engine off time. put about 5 OZ of marvel mystery oil in the engine oil and this over the life of the oil you just installed should gradually remove the deposits. since this is intermittent my guess is it is just a carbon/contamination problem.

replace the PCV . this valve wears out and if it does not work properly will cause carbon issues. make sure all rubber lines are perfect with no defects.

[biznazion]

The frequency of 'ticking' seems to be greatly reduced. I've been trying to get the cooling system sealed up again but having a lot of problems. I had the truck into a shop to have the intake resealed. The shop that did the reseal told me there was a quite a bit of 'gunk' in the lifter galley so they vaccumed it all up for me. A couple days after getting it home, I noticed some coolant dripping near the front fenders (both sides). Investigation showed a coolant soaked drivers side plastic tank on the radiator. Checked the top hose and it was tight - and could not see any leaks when running in the garage, but test drive produced leakage. The tray the radiator sits in was full of coolant and running out both sides. I replaced the radiator and two days later I have coolant leaking from the water pump. So, I'm wondering if I just have bad luck or is there something I'm missing that's causing these other failures in the cooling system. The truck has 157K on it, and the water pump may be the original, but the radiator was less than 3 years old.

[j cAT]

with the GUNK in the lifter valley this is why I say no to dino oil in these engines with the use of alcohol fuels !

with the marvel mystery oil this will reduce this build up. if you continue to use non synthetic then this gunk will grow again and cause engine noise/dirty lifters.

you need a shop to pressure test your coolant system.. use of leak detector dye to find leaks..

could be the water pump leak is at the WEEP hole or at the engine water pump gaskets... try to re-torque the water pump bolts.

[SleepyHead98]

I second the USE SYNTHETIC opinion above. Got a 3.1l gm, started ticking, almost metalic tapping. Switched to synthetic, hasent reared its head in over 6 months. 252k mi on it. As far as the leaks. Sounds like the shop screwed up. If it wasnt leaking b4 you took it and now it is, I would question that. Also, could be that the water pump is just dying out, they should have aweep holes on them, and if it starts to leak, its about to go out, like soon. As far as the coolant coming from the surge tank, IF I read that right, Maybe there was an air bubble from when they removed the manifold and what not.

[biznazion]

The truck was indeed leaking before I took it to the shop. I had a small manifold leak that I "lived with" for over a year. Recently it started leaking heavily from the opposite side and at that point I had to have the intake resealed. The shop did a great job on the manifold - I don't believe their work and anything to do with the additional component failures. After replacing the radiator, waterpump and cap the truck is again leak free. Getting the fan nut off was a real bear - I ended up chaining one of the pulley bolts to the frame cross member. I had the shop put mobile1 back in the truck after the intake job and will stay with synthetic going forward.

[j cAT]

Originally Posted by biznazion

The truck was indeed leaking before I took it to the shop. I had a small manifold leak that I "lived with" for over a year. Recently it started leaking heavily from the opposite side and at that point I had to have the intake resealed. The shop did a great job on the manifold - I don't believe their work and anything to do with the additional component failures. After replacing the radiator, waterpump and cap the truck is again leak free. Getting the fan nut off was a real bear - I ended up chaining one of the pulley bolts to the frame cross member. I had the shop put mobile1 back in the truck after the intake job and will stay with synthetic going forward.

the water pump fan nut is a tough one. that is reverse thread I think ?

[biznazion]

The fan nut is normal thread - remove in counterclockwise direction. My saga continues. I now have a leak at the heater control valve.

[biznazion]

I've replaced the heater control valve, but unfortunately, I've still got a leak there on cold start. Seems to be coming from the place where the lever is. Only leaks a little bit and then stops. There is a vaccum line that runs to the heater control valve - I'm wondering if that could be part of the problem - there really isn't much else that can go wrong with a plastic tee.

Since the truck has been able to hold cooant level, the ticking has ceased completely.

[j cAT]

Originally Posted by biznazion

I've replaced the heater control valve, but unfortunately, I've still got a leak there on cold start. Seems to be coming from the place where the lever is. Only leaks a little bit and then stops. There is a vaccum line that runs to the heater control valve - I'm wondering if that could be part of the problem - there really isn't much else that can go wrong with a plastic tee.

Since the truck has been able to hold coolant level, the ticking has ceased completely.

funny how this has been going on for months and with you heater control issue I just figured out this is an OBS tahoe ...not the NBS ..