tick tick goes the 4.0 ?
02-10-11, 05:04 AM
#16
Lexus Champion
The moment I saw this thread I knew that the EGR pipe was cracked.
02-10-11, 06:17 AM
#17
Have you actually seen that on this model of engine?
Any potential long-term damage to anything as a result (that you know of)?
Like from hot exhaust gasses hitting anything nearby like hoses or wiring or plastic stuff?
Since the cams are fine and the valve clearances are all in spec on my car, if it's not internal to the head (like a valve seat or something along those lines) and really is something like a cracked EGR pipe, do I need to be concerned or can I just relax and live with it?
Any potential long-term damage to anything as a result (that you know of)?
Like from hot exhaust gasses hitting anything nearby like hoses or wiring or plastic stuff?
Since the cams are fine and the valve clearances are all in spec on my car, if it's not internal to the head (like a valve seat or something along those lines) and really is something like a cracked EGR pipe, do I need to be concerned or can I just relax and live with it?
02-11-11, 09:08 PM
#20
So I'm wondering, I spend at least 2 hours a day out on the interstate so should I be concerned about exhaust gasses getting sucked into the cabin through the "fresh" vent mode if the EGR pipe is cracked and leaking at the back of the engine near the hood cowl as I cruise down the interstate?
When I first bought the car it was smoking out the exhaust because it was literally drinking/burning power steering fluid, thanks to a bad vacuum valve on the power steering pump, and there would actually be a quick puff of smoke coming out of the hood by the windshield whenever I started the car which we discovered was coming from the EGR area whenever the hood was open.
That smoke puff along the windshield on startup stopped being noticeable when we replaced the power steering vacuum valve because the engine's no longer burning power steering fluid but that doesn't mean the vapors aren't still being vented in that same area...
When I first bought the car it was smoking out the exhaust because it was literally drinking/burning power steering fluid, thanks to a bad vacuum valve on the power steering pump, and there would actually be a quick puff of smoke coming out of the hood by the windshield whenever I started the car which we discovered was coming from the EGR area whenever the hood was open.
That smoke puff along the windshield on startup stopped being noticeable when we replaced the power steering vacuum valve because the engine's no longer burning power steering fluid but that doesn't mean the vapors aren't still being vented in that same area...
02-12-11, 07:15 AM
#21
Lexus Champion
so just fix it !!!
02-12-11, 07:49 PM
#23
Lexus Test Driver
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i dont know ours doesnt smoke from there so its gotta be the valve adjustment on ours.. im not tearing it apart just for that though since the valve stem seals arent even smoking and the timing belts etc. is good maybe one day if i have extra time and money for it..
02-13-11, 12:02 PM
#24
It could be an exhaust leak in the manifold like you suspect. Here are a couple of my hair-brained ideas: Get a mechanics stethoscope and start probing. These stethoscopes look similar to a doctors but with a large metal tip instead of disc. They can be very useful and with some training, you should be able to locate the noise and discern between a metallic tap (of the valves) and an exhaust leak. And/or try a thicker viscosity of oil or the Marvel oil mentioned. If the tick changes, you have a mechanical clearance issue.
02-13-11, 09:12 PM
#25
Hey Randal, thanks for the stethoscope suggestion. I'm used to the old "really big screwdriver pressed against my ear" method to try to isolate things but a steth does make it easier to tell one type of sound from the other for sure. I'm not used to the sounds of a steth yet so I still haven't spent the time to learn to use one...
For the moment even with all the problems I've already fixed I've still got non-retracting front seat belts that are waaaay too loose for me and headlights that don't adjust and are pointed so far down and up (one at the bumper and one at the sky) that I can't see well at night (thank god the fog lights work so well!) and all of the ones in the junkyard yesterday (ALL EIGHT 90-94 LS400's!) had broken/inoperable headlight adjusters too
, and really warped front brakes on my to-do list as those things actually effect drivability and personal safety and I'm just leaving the vent mode in recirc at all times for now 'till I get a chance to go probing for the clack which seems to be mildly to moderately audible at idle at all times and can even be heard while driving on mild accelleration more times than not but does actually go away sometimes...
Hey Will,
Valve clearances are very easy to check. Get a set of "feeler gauges" that includes the size ranges specified in the Lexus service manual for the 1UZ-FE engine, typically included in most feeler gauge sets and readily available at many auto parts stores, then remove the valve covers (a.k.a. cam covers), manually turn the crankshaft to the proper position for the cam lobes on the cylinder you want to check to be pointing directly away from that cylinder's valves (not pushing them open), then try to stick a feeler in between the cam and the valve shim one feeler after another until you find one that fits then read the number off the feeler and that's the clearance. You shouldn't have to force it, it should slide in fairly easy.
They don't all have to be exactly the same, ideally they just have to be within the range specified in the service manual for optimum engine operation and they won't go from quiet to loud if they're not exactly in that range unless one is VERY different from the stated spec range...
Changing shims with the cams still in the head requires a neat little tool and a little practice to get the hang of using it but once you figure it out it's truly simple to replace a valve shim without taking the head apart. They can be somewhat brand specufic (Toyota/Lexus) and even engine specific to some extent and I don't remember where our local machine shop owner bought the tools we needed for our 7M and 2JZ Supras and 3S/5S-FE Camry motors but she said they aren't expensive and were easy to find and the same tool worked on both the 7M and 2JZ engines for our Supras.
Also, you aren't going to need all 32 shims so it's NOT expensive like the $10-$15 (or more from greedy vendors) per shim x32 valves that some people seem to suggest would be needed. Yes shims are a bit pricy per shim but I've found on most Toyota I4 and I6 engines that have never been checked and have well over 100k miles on 'em if not 200k, they usually need anywhere from 1 to 5 shims at most and that's typically as they approach or exceed 200k miles, unless of course cheap oil was used all its' life and wasn't changed regularly and even then I've never seen all of the shims need to be replaced, or even as many as half of them out of spec, seriously, although this is my first 1UZ, I'm owner #3, and the service history of the car is totally unknown but my heads and cams are still beautifully light golden oily with no signs of sludge or neglect and all my valves are still in spec, even with the odometer saying 185k miles.
Plus I've had a case where a Toyota I6 engine had been "rebuilt" by some clueless domestic engine mechanic less than 10k miles before my buddy bought the car and it literally sounded like a diesel clacking away on all cylinders, it was that bad! In that case only ONE valve out of the I6 engine's 24 valves was actually IN factory spec and he didn't have the money for shims and we didn't have enough spares to get most of 'em back into spec so I just played musical shims on all 24 valves, just documented everything (starting clearances and starting shim thicknesses) and then did the math for each valve and rearranged them all until they were still out of spec but pretty close to being back in spec and that engine ran so smooth and quiet and actually had power again when I was done and he was very happy. Six months and 15k miles later he sold the car still running smooth and quiet like a champ and disclosed what we did to the buyer who didn't care.
Oh, and you can't get to the valve stem seals and replace them while the heads are still on the engine without a LOT of work involving removal of the cams and a lot of rope and/or a big air compressor to start out with and it's NOT fun to do the job that way...
It's far more work to do valve stem seals with the engine still intact than what's involved in checking valve clearances which isn't much more difficult than changing spark plugs really... Replacing out of spec shims with the cams still in does take a bit of practice with that special tool before it gets easy but checking them to rule them out as a source of mild ticking or even loud clacking is pretty easy if you're mechanically inclined.
For the moment even with all the problems I've already fixed I've still got non-retracting front seat belts that are waaaay too loose for me and headlights that don't adjust and are pointed so far down and up (one at the bumper and one at the sky) that I can't see well at night (thank god the fog lights work so well!) and all of the ones in the junkyard yesterday (ALL EIGHT 90-94 LS400's!) had broken/inoperable headlight adjusters too
, and really warped front brakes on my to-do list as those things actually effect drivability and personal safety and I'm just leaving the vent mode in recirc at all times for now 'till I get a chance to go probing for the clack which seems to be mildly to moderately audible at idle at all times and can even be heard while driving on mild accelleration more times than not but does actually go away sometimes... Hey Will,
Valve clearances are very easy to check. Get a set of "feeler gauges" that includes the size ranges specified in the Lexus service manual for the 1UZ-FE engine, typically included in most feeler gauge sets and readily available at many auto parts stores, then remove the valve covers (a.k.a. cam covers), manually turn the crankshaft to the proper position for the cam lobes on the cylinder you want to check to be pointing directly away from that cylinder's valves (not pushing them open), then try to stick a feeler in between the cam and the valve shim one feeler after another until you find one that fits then read the number off the feeler and that's the clearance. You shouldn't have to force it, it should slide in fairly easy.
They don't all have to be exactly the same, ideally they just have to be within the range specified in the service manual for optimum engine operation and they won't go from quiet to loud if they're not exactly in that range unless one is VERY different from the stated spec range...
Changing shims with the cams still in the head requires a neat little tool and a little practice to get the hang of using it but once you figure it out it's truly simple to replace a valve shim without taking the head apart. They can be somewhat brand specufic (Toyota/Lexus) and even engine specific to some extent and I don't remember where our local machine shop owner bought the tools we needed for our 7M and 2JZ Supras and 3S/5S-FE Camry motors but she said they aren't expensive and were easy to find and the same tool worked on both the 7M and 2JZ engines for our Supras.
Also, you aren't going to need all 32 shims so it's NOT expensive like the $10-$15 (or more from greedy vendors) per shim x32 valves that some people seem to suggest would be needed. Yes shims are a bit pricy per shim but I've found on most Toyota I4 and I6 engines that have never been checked and have well over 100k miles on 'em if not 200k, they usually need anywhere from 1 to 5 shims at most and that's typically as they approach or exceed 200k miles, unless of course cheap oil was used all its' life and wasn't changed regularly and even then I've never seen all of the shims need to be replaced, or even as many as half of them out of spec, seriously, although this is my first 1UZ, I'm owner #3, and the service history of the car is totally unknown but my heads and cams are still beautifully light golden oily with no signs of sludge or neglect and all my valves are still in spec, even with the odometer saying 185k miles.
Plus I've had a case where a Toyota I6 engine had been "rebuilt" by some clueless domestic engine mechanic less than 10k miles before my buddy bought the car and it literally sounded like a diesel clacking away on all cylinders, it was that bad! In that case only ONE valve out of the I6 engine's 24 valves was actually IN factory spec and he didn't have the money for shims and we didn't have enough spares to get most of 'em back into spec so I just played musical shims on all 24 valves, just documented everything (starting clearances and starting shim thicknesses) and then did the math for each valve and rearranged them all until they were still out of spec but pretty close to being back in spec and that engine ran so smooth and quiet and actually had power again when I was done and he was very happy. Six months and 15k miles later he sold the car still running smooth and quiet like a champ and disclosed what we did to the buyer who didn't care.
Oh, and you can't get to the valve stem seals and replace them while the heads are still on the engine without a LOT of work involving removal of the cams and a lot of rope and/or a big air compressor to start out with and it's NOT fun to do the job that way...
It's far more work to do valve stem seals with the engine still intact than what's involved in checking valve clearances which isn't much more difficult than changing spark plugs really... Replacing out of spec shims with the cams still in does take a bit of practice with that special tool before it gets easy but checking them to rule them out as a source of mild ticking or even loud clacking is pretty easy if you're mechanically inclined.
02-14-11, 05:46 PM
#26
Pole Position
checking valve clearances which isn't much more difficult than changing spark plugs really...
02-15-11, 06:48 PM
#27
If it was that easy to adjust these valves I think everyone would do it and not live with the "tick". The problem is the labor involved in getting down to them to adjust them. (unless you're already in there) Taking these valve covers off is time consuming, with the throttle body and everything else. That's why the dealer charges soo much for the job. I should have done mine while I had the valve covers off but I just wasn't thinking. I aint takin those covers off again.
02-15-11, 07:47 PM
#28
Pole Position
Yes he did say "checking" them but I did mention the hard part is "getting down to them" And if you went through all that trouble removing the valve covers to "check" the clearance, why wouldn't you "adjust" them? I just figured I would point out to any newbie that there is way, WAY more labor involved then just the 15 easy minutes to change spark plugs. So, it is ALOT more difficult to "check" the valve clearance, on this engine, then to change spark plugs.
02-22-11, 01:17 PM
#30
You're right, not all newbies should even be poking around inside their engine bays whatsoever...
So let's just put it this way instead.
If you're overwhelmed by trying to remove your valve covers then you should definitely seek help with this and NOT try to do it yourself!
If you have some time and can figure out how to properly get the valve covers off and back on again, then you can figure out how to check the valve clearances to see IF that's your problem or not.
Don't expect to get in there and replace a bunch of shims and have the car back together quickly one morning, that was NOT my intended point. BUT I still believe that if you have the mechanical "where with all" to get the valve covers off you can easily inspect your valve clearances yourself and get the car back together without some huge ordeal...
If you find things all good with all clearances still in spec then reassemble and you're done. If you find some valves in need of attention (out of spec) you can either get involved in learning to re-shim them at that time which is a good bit more involved or you can simply document your findings and reassemble the car and form a plan for a better time to tackle re-shimming any valves that are in need when you are better prepared to try and change them...
If something doesn't end up needing adjustment, then why would you adjust it?
All 32 of my car's valves were still within spec even with the odometer saying 185,000 miles and that's been the case with most of the high mileage Toyota engines I've owned over the past 20+ years that didn't have some other major mechanical problem...
I guess it's all in what you're used to as to how simple, easy, or hard something is.
Granted this is my first 1UZ experience and I'm mostly used to Toyota's various I6 platforms of years past, I'm used to having to remove a throttle body and sometimes an intake plenum and in some cases with some of the FWD Toyota V6's and such a motor mount or two or even a manifold just to change spark plugs these days and dealing with factory turbochargers and the related spaghetti of intake piping and such as well so when it comes to pulling the valve covers off the 1UZ it just doesn't seem all that hard to me really.
But again, if you can't figure out how to get your valve covers off or can't do it without breaking anything in the process then "don't try this at home!" with regards to checking and/or "adjusting" your 1UZ's valves...
So let's just put it this way instead.
If you're overwhelmed by trying to remove your valve covers then you should definitely seek help with this and NOT try to do it yourself!
If you have some time and can figure out how to properly get the valve covers off and back on again, then you can figure out how to check the valve clearances to see IF that's your problem or not.
Don't expect to get in there and replace a bunch of shims and have the car back together quickly one morning, that was NOT my intended point. BUT I still believe that if you have the mechanical "where with all" to get the valve covers off you can easily inspect your valve clearances yourself and get the car back together without some huge ordeal...
If you find things all good with all clearances still in spec then reassemble and you're done. If you find some valves in need of attention (out of spec) you can either get involved in learning to re-shim them at that time which is a good bit more involved or you can simply document your findings and reassemble the car and form a plan for a better time to tackle re-shimming any valves that are in need when you are better prepared to try and change them...
If something doesn't end up needing adjustment, then why would you adjust it?
All 32 of my car's valves were still within spec even with the odometer saying 185,000 miles and that's been the case with most of the high mileage Toyota engines I've owned over the past 20+ years that didn't have some other major mechanical problem...
I guess it's all in what you're used to as to how simple, easy, or hard something is.
Granted this is my first 1UZ experience and I'm mostly used to Toyota's various I6 platforms of years past, I'm used to having to remove a throttle body and sometimes an intake plenum and in some cases with some of the FWD Toyota V6's and such a motor mount or two or even a manifold just to change spark plugs these days and dealing with factory turbochargers and the related spaghetti of intake piping and such as well so when it comes to pulling the valve covers off the 1UZ it just doesn't seem all that hard to me really.
But again, if you can't figure out how to get your valve covers off or can't do it without breaking anything in the process then "don't try this at home!" with regards to checking and/or "adjusting" your 1UZ's valves...