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So for the last few weeks Upon start up of my 2002 Toyota Tundra there has been an obnoxiously loud exhaust noise. This noise sounds like what I thought was probably cracked exhaust manifolds. Sound producible mostly when the engine is cold. It sounds like a cut off exhaust essentially, the best I can describe it. So I went to inspect the exhaust system today and everything appears to be intact except I have not gotten to the part of removing the heat shields to inspect the manifolds. Anyways during inspection I have noticed grime and gunk on top of my driver sides header which appears to be coming front the bolts. It has not dropped down onto the exhaust manifold shield yet. Can anyone tell me if I have a bad head gasket/cracked cylinder head or is this just caused by the bad manifold possibly? My oil appears fine without milky substance, the coolant appears fine and my truck is not over heating. Any pointers or insight would be great!
 

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Looks more like a valve cover leak, you may get lucky and just need to tighten the 9 bolts that hold it the cover on. I had a similar leak, it wasn't as messy as yours, but same areas. I figured the gasket was bad, but when I checked the valve cover bolts to see if any are loose, half of mine could be turned with finger pressure, I snugged em up and washed the grime off. hasn't been a problem since. bolt spec is 53 INCH/lbs not foot /lbs.
 

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Looks more like a valve cover leak, you may get lucky and just need to tighten the 9 bolts that hold it the cover on. I had a similar leak, it wasn't as messy as yours, but same areas. I figured the gasket was bad, but when I checked the valve cover bolts to see if any are loose, half of mine could be turned with finger pressure, I snugged em up and washed the grime off. hasn't been a problem since. bolt spec is 53 INCH/lbs not foot /lbs.
Wow! Thanks for posting, I’m so glad you did. I went down and checked the bolts and sure enough some of them especially where it was very grimy were loose! Well I hope this solves some of the issue. Wonder if this was what was causing the ripping exhaust noise or of the manifolds are still probably cracked. The only issue I’ve had for so long is an engine ticking noise that goes away after it warms up. Exhaust manifold related or the fact that my cylinder header wasn’t fully attached to the block
 

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I did notice the engine got quieter with the valve cover not loose, but the ticking I am afraid is not likely to go away. The valve train is always noisy before the oil is fully circulated, and those stock manifolds are common leak points . Both cause the noise you describe. Now go clean off all that grime on your valve covers so you can make sure you notice when they rattle out again. 8k since I did mine still leak free.
 

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Since you just saved yourself $1000 dollars on a head gasket replacement, You might also want to inspect/replace your pcv valve. Seems to me that if the pressure cant get out the pcv valve it has to put stress on the vc gasket, which may contribute to why yours came loose to begin with. they are less than 15 bucks takes just a few minutes if its not corroded in place. Check the condition of the hose it outlets too also, is it leaking oil at the hose connections? Those hoses are often brittle and cooked, and the stock spring clamps loose their grasp. Swap it for fresh and replace the spring clamps with hose clamps. Whole shebang is less than $25, and less than 30 min.
 

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Since you just saved yourself $1000 dollars on a head gasket replacement, You might also want to inspect/replace your pcv valve. Seems to me that if the pressure cant get out the pcv valve it has to put stress on the vc gasket, which may contribute to why yours came loose to begin with. they are less than 15 bucks takes just a few minutes if its not corroded in place. Check the condition of the hose it outlets too also, is it leaking oil at the hose connections? Those hoses are often brittle and cooked, and the stock spring clamps loose their grasp. Swap it for fresh and replace the spring clamps with hose clamps. Whole shebang is less than $25, and less than 30 min.
Good thing to know 00-02 use a push in PCV valve so plan on having a new grommet for the valve cover too. 03-06 use a screw in type PCV.
00-02 grommet 90480-18001
00-02 PCV 12204-50020
03-06 PCV 12204-50030
 

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I wonder if it had been loose like that for awhile, I had just replaced the pcv valve last summer when I was doing a tune up. What is the average life of one of these valves?
truck seems to be running much more right, but I’m still getting an extremely loud exhaust rip noise upon start up. Any of you experience this, think it’s my exhaust headers? Shouldn’t be anything else that could cause this problem noise?
 

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1 year your pcv is likely fine. I like to do it at 100k then at every 50k as it is cheap and easy. oem will go 100k plus, but as your engine ages it is gonna last a shorter time. On that exhaust issue, no I don't have a noticeable leak, but my valve train is pretty noisy at startup quiets a little after a minute or two than quiets again once the oil is up to temp. I've see a lot of pictures of factory exhaust manifolds with holes in em. So I know its not uncommon. But it really could be downstream and just echoes as if it is at the block. I would stick a shop vac/ leaf blower/ hair dryer in reverse/blow mode and duct tape it to your exhaust pipe while engine is cold and off. crawl under and spray the whole line with soapy water. It'll blow bubbles at all your leaks. That egine layout doesn't make for easy inspection / access to the exhaust from the hood, so no fun. I would ensure everything easy is sealed up first.
 

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View attachment 151659 View attachment 151660 View attachment 151661 So for the last few weeks Upon start up of my 2002 Toyota Tundra there has been an obnoxiously loud exhaust noise. This noise sounds like what I thought was probably cracked exhaust manifolds. Sound producible mostly when the engine is cold. It sounds like a cut off exhaust essentially, the best I can describe it. So I went to inspect the exhaust system today and everything appears to be intact except I have not gotten to the part of removing the heat shields to inspect the manifolds. Anyways during inspection I have noticed grime and gunk on top of my driver sides header which appears to be coming front the bolts. It has not dropped down onto the exhaust manifold shield yet. Can anyone tell me if I have a bad head gasket/cracked cylinder head or is this just caused by the bad manifold possibly? My oil appears fine without milky substance, the coolant appears fine and my truck is not over heating. Any pointers or insight would be great!
I have the same noise when cold start since I purchased a year ago at 194k miles. Now 201k and still for only no more than 2 minutes or less then it stops. It doesn't get hot enough to expand the components to self seal, so I don't think it's a crack. It must be some type of bypass valve or something that closes to stop noise. I really don't have a clue and have not looked into it to deeply. I have not seemed to have any problems resulting from ignoring it. It would be nice to know since it is a little annoying not knowing.
 

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I changed the Driver's Side VC gasket, seals that were leaking and found some oil blow by in the spark plug holes. Got the OEM gaskets and Toyota Block Sealant and changed all plugs & ignition coils, PCV, R&R/cleaned the throttle body as well, saving the old coils as still working for backup(a new one faulted after 5 months, so that saved me). It is a necessary task at some point, and now it is time for Passenger Side as seeing oil getting past those seals to plugs though no VC gasket leaks.
And YES, the VC bolts were all loose, so if that fix stops the worst of it, great. Also, checking the torque on spark plugs, including 1K after installing new is great practice.
Our older Tundras need and deserve all the Love we can afford to give them, but soooo worth the efforts. And the fun never stops!!!
As I already have most every part needed for the front end for total rebuild, this current time of zero employment or income is perfect to get that job done NOW!
Hunker Down & Stay Safe all my Toyota Peeps and Families.
We will get on down the road together hopefully Stronger than Ever!
 
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