That would require (believe it or not...) a complete redesign of the suspension.
Engine rattles on startup
- Thread starter Telco
- Start date
That would require (believe it or not...) a complete redesign of the suspension.
1LoudLS
Dedicated LVC Member
actually I quite do understand what would be involved in such a change, and its something that automotive manufacturers do all the time. sure there is lazy ass selling the same car twice routine like the taurus/sable or silverado/sierra, with no real difference between the two. but they also will modify platforms create other platforms, like taking the D3 platform for the taurus and then modifying it into the longer and WIDER D4 platform for the flex and explorer.
but we are not even talking about say using an older DEW platform for a brand new model like the XF years later instead of designing something new, or choosing to use a different platform after its already been out for half a decade because they realized that you couldn't fit a proper V8 in it like the mustang would need (lets face it, ford is not going back to narrow pushrod motors anytime soon)...
here we are talking about both car being designed at the same time and more importantly, creating the platform itself as both the LS and S-Type were the first cars to use it for their 2000 model years. you are talking about engineering everything from the beginning, there is no redesigning the entire thing, there is only making those decisions to do that the first time. it would not have been any more work for them to design the width of the chassis to support the widest of the engine they wanted to use if they would had wanted to use a mod motor as one of the options.
Telco
Dedicated LVC Member
An engineer... who can't modify his own design... is not much of an engineer. There are thousands upon thousands of people out there who make major modifications to vehicles in their own back yards, many of them do such a good job that people can't believe it didn't come that way from the factory, and you are claiming an engineer with all the resources of Ford behind him can't do the same?
No. I'm saying that manufacturers have to build to a price point, longevity and they are constrained by a time-line. The Shadetree has unlimited time and he doesn't have to consider assembly-line mass production. Who knows how long the Shadetree's modifications will last.
Besides, once a car is designed the engineers move on to the next project.
joegr
Dedicated LVC Member
He also doesn't have the expenses of crash testing and regulatory compliance. You (Telco) may insist that you would do things differently, but you would be fired for ignoring the objectives that you were given to design to.
Telco
Dedicated LVC Member
If the engineer were tasked with installing a 4.6 into an LS, which I was given to understand was their objective, should they not have been fired for not being able to make it work? I mean, if I had Ford's equipment and expertise to back me up I could stick a 4.6 into an LS and make it work no problem. How could Ford's own engineers not be able to make it work? If sticking a 4.6 into the LS and making it work was the objective, how could I be fired for ignoring the objective? Does the engine not already physically fit in the engine bay? Is it really that hard for an engineer to modify shock tower mounts on a unibody vehicle? This isn't rocket science, and the LS is just a car like any other one.
04_Sport_LS
Dedicated LVC Member
Originally Posted by LS4me...
Are you an automotive engineer? Having heard directly from the horse's mouth this wasn't possible. There is infinitely more involved than than just widening the uni-body a little. That's why the Mustang didn't use the DEW98. There is a law of unintended consequences....... (end quote)
Not being an engineer, (but at the same time not being a complete idiot),,, I don't see why widening the unibody would be necessary. The front strut towers are spot welded in,,, so they are a separate piece of preformed sheet metal. Looking at pics of the S-Type engine compartment,,, the Jag front strut towers are shaped differently. So that means Ford was already using a different stamping die from the Jag. During pre-production design of the LS,,, the strut towers could have been designed with a dent, recess, (whatever you want to call it), so that 4.6 would have fit better. There are places on the net where others have stuffed different engines in the LS,,, and made this recess themselves to fit the engine.
Now with the extra weight of the all aluminum 4.6,,, obviously the front springs and struts would have to be stiffer... but at the same time,,, the engine cradle would have to be redesigned. But beyond that... would the extra weight of the 4.6 cause failure of the front aluminum control arms when pushing the LS to its limits??? Also,,, the extra weight of the 4.6 would obviously shift the neutral handling of the LS to the front,,, giving the car a bit of oversteer. Yeah... I'm no engineer... but don't think I haven't thought about,,, or don't understand design concepts and limitations.
Originally Posted by LS4me...
That would require (believe it or not...) a complete redesign of the suspension. (end quote).
Really??? Kinda like Ford actually did with the SVT Cobra??? Imagine an SVT LS!!! It could have been done,,, while adding roughly $5k-$7k to the sticker price, (as long as the vehicle would have still been safe to drive). But as the 4 of us have all said, (in different ways)... Ford stayed within the confines of a practical, saleable, grocery getting, business man driving vehicle... with enough performance to make most people happy. The very least Ford should have done... is re-design the rear suspension cradle to fit a 28 spline 8.8,,, and done something different with the rear LCA bushings.
Beyond that... my biggest reason for stating the 4.6 Intech as a better engine for the LS,,, is simply for better performance over the 3.9... without using VVT/VCT.
Of course this is all a pipe dream,,, and nothing more than shoulda, coulda, woulda.... and Ford will never build anything, (reasonably priced), that could have the potential of outshining their beloved pony car.
If this ends up as a double post... I apologize. I'm having internet problems today.
Are you an automotive engineer? Having heard directly from the horse's mouth this wasn't possible. There is infinitely more involved than than just widening the uni-body a little. That's why the Mustang didn't use the DEW98. There is a law of unintended consequences....... (end quote)
Not being an engineer, (but at the same time not being a complete idiot),,, I don't see why widening the unibody would be necessary. The front strut towers are spot welded in,,, so they are a separate piece of preformed sheet metal. Looking at pics of the S-Type engine compartment,,, the Jag front strut towers are shaped differently. So that means Ford was already using a different stamping die from the Jag. During pre-production design of the LS,,, the strut towers could have been designed with a dent, recess, (whatever you want to call it), so that 4.6 would have fit better. There are places on the net where others have stuffed different engines in the LS,,, and made this recess themselves to fit the engine.
Now with the extra weight of the all aluminum 4.6,,, obviously the front springs and struts would have to be stiffer... but at the same time,,, the engine cradle would have to be redesigned. But beyond that... would the extra weight of the 4.6 cause failure of the front aluminum control arms when pushing the LS to its limits??? Also,,, the extra weight of the 4.6 would obviously shift the neutral handling of the LS to the front,,, giving the car a bit of oversteer. Yeah... I'm no engineer... but don't think I haven't thought about,,, or don't understand design concepts and limitations.
Originally Posted by LS4me...
That would require (believe it or not...) a complete redesign of the suspension. (end quote).
Really??? Kinda like Ford actually did with the SVT Cobra??? Imagine an SVT LS!!! It could have been done,,, while adding roughly $5k-$7k to the sticker price, (as long as the vehicle would have still been safe to drive). But as the 4 of us have all said, (in different ways)... Ford stayed within the confines of a practical, saleable, grocery getting, business man driving vehicle... with enough performance to make most people happy. The very least Ford should have done... is re-design the rear suspension cradle to fit a 28 spline 8.8,,, and done something different with the rear LCA bushings.
Beyond that... my biggest reason for stating the 4.6 Intech as a better engine for the LS,,, is simply for better performance over the 3.9... without using VVT/VCT.
Of course this is all a pipe dream,,, and nothing more than shoulda, coulda, woulda.... and Ford will never build anything, (reasonably priced), that could have the potential of outshining their beloved pony car.
If this ends up as a double post... I apologize. I'm having internet problems today.
I have been following this thread for sometime since I have acquired a very nice, low mileage and nearly perfect 2005 Thunderbird. The only issue is with the engine rattle on start-up; as described exactly on this thread with the LS ( Thunderbird has same engine and suffers from the same condition.) There is a fix since I have had mine fixed. The fix is: New cam chain tensioners (both primary and secondary), new cam phasers (both sides), new chain guides. The labor cost is 14.8 hrs and close to a Grand in parts for a total of $2600. The only good thing here is its fixed and guaranteed to stay fixed for two years or will be fixed for free (this eliminates the chance of putting problematic parts in from Ford or Jaguar or where ever they come from. I plan to keep this car for a long time so for me it was worth the cost. For all that want to know what the cause or fix is for this condition; Well this is it.
Regards:
cmf
kevinspann
Active LVC Member
I'd wager it was the cam phasers, but I don't know how to test/check them.
Engine tattle
Just want to make this one last point on the engine start-up rattle/noise on the AJ35 engine. The idea that one can keep on driving with this rattle may not be a good idea. The engine rattle on start-up is the timing chain rubbing on something inside the engine (very likely the engine block) so there will be damage with every start-up, either to the chain itself or what ever it is rubbing on or both. To not fix this condition could cost you a new engine.IMHO.
Regards:
cmf
Best test is to replace them!
Just want to make this one last point on the engine start-up rattle/noise on the AJ35 engine. The idea that one can keep on driving with this rattle may not be a good idea. The engine rattle on start-up is the timing chain rubbing on something inside the engine (very likely the engine block) so there will be damage with every start-up, either to the chain itself or what ever it is rubbing on or both. To not fix this condition could cost you a new engine.IMHO.
Regards:
cmf
mpd4200
LVC Member
So, yesterday I had what I thought was a coil go bad, rough idle. I hooked up my PC driven Autoenginuity to the LS for the first time. I found that I can measure/read cam timing. I'm curious to see if I can use this scanner to show a story behind the rattle at start up.
Anyone ever try this?
Anyone ever try this?
04_Sport_LS
Dedicated LVC Member
An interesting article on cam phasers can be found here. For the basics... jump down to paragraph #10 and the rest.
http://www.expertswrite.net/tech/31-tech-train/ford-5-4l-triton-3valve/33-ford-vvt.html
Keep in mind this is for the 5.4 3V,,, but the same basic principals apply to the LS. Also, some of the other links on the page are very informational.
There are cam phaser "lockout" kits for the 4.6 and 5.4 engines, (not that they would fit the 3.9), but they require a reprogam of the computer... which is probably not available for the LS 3.9 . Not to mention that you will be takeing a Gen II engine back to Gen I HP and torque specs.
I also did some searching on the 4.6 LS engine overheating issues. Ford paticipated in a "one day race" and stuffed a supercharged 4.6 down in the LS for that race. Yes the engine torched,,, but as the story continues... they cannibalized another vehicle for a second SC 4.6 and after 11 hours were able to get back into the race. My idea mentioned in above posts,,, was not for a supercharged 4.6,,, but a natually aspirated 4.6... so the overheating most likely wouldn't be an issue.
Further rersearch shows that Ford was considering building a high performance version of the LS. However,,, with the joint development of the DEW 98 platform being a joint venture between Ford and Jag... Jaguar was given priority over Ford as far as funding. Plus Jag was whining that if ford built a HP LS for a cheaper retail price than the Jag,,, it would undercut Jag sales. So.. in the end,,, Jag took Ford's money and ran with it, (resulting in the financial woes Ford had when Bill Ford stepped down), and continued development on the DEW 98 platform.
All again... woulda coulda shoulda,,, but a 4.6 version of the LS was in the works at one point.
http://www.expertswrite.net/tech/31-tech-train/ford-5-4l-triton-3valve/33-ford-vvt.html
Keep in mind this is for the 5.4 3V,,, but the same basic principals apply to the LS. Also, some of the other links on the page are very informational.
There are cam phaser "lockout" kits for the 4.6 and 5.4 engines, (not that they would fit the 3.9), but they require a reprogam of the computer... which is probably not available for the LS 3.9 . Not to mention that you will be takeing a Gen II engine back to Gen I HP and torque specs.
I also did some searching on the 4.6 LS engine overheating issues. Ford paticipated in a "one day race" and stuffed a supercharged 4.6 down in the LS for that race. Yes the engine torched,,, but as the story continues... they cannibalized another vehicle for a second SC 4.6 and after 11 hours were able to get back into the race. My idea mentioned in above posts,,, was not for a supercharged 4.6,,, but a natually aspirated 4.6... so the overheating most likely wouldn't be an issue.
Further rersearch shows that Ford was considering building a high performance version of the LS. However,,, with the joint development of the DEW 98 platform being a joint venture between Ford and Jag... Jaguar was given priority over Ford as far as funding. Plus Jag was whining that if ford built a HP LS for a cheaper retail price than the Jag,,, it would undercut Jag sales. So.. in the end,,, Jag took Ford's money and ran with it, (resulting in the financial woes Ford had when Bill Ford stepped down), and continued development on the DEW 98 platform.
All again... woulda coulda shoulda,,, but a 4.6 version of the LS was in the works at one point.
Yes, the operative word in your reply is "Always" and I know you are probably correct in your statement; However in my AJ35/Gen II V8 there were tensioners broken as well as some that obviously weren't holding prime. There were marks where the chain had actually gotten on the engine block (that is what was making the rattling noise). The cam phasers were replaced as a matter of elimination (don't really know if they were bad). The cam bearings were determined by my mechanic to be fine. The car has 42.000 mile and other than the start-up noise ran quiet and smooth.
Regards:
cmf
04_Sport_LS
Dedicated LVC Member
MPD4200,
That's actually not a bad idea. But you would also need an oil pressure test gauge. That way you could observe any fluctuations in cam timing,,, up to the point the engine reaches 22 PSI... which is when oil pressure is restored to the cam phasers after leaking down. However this may not be 100% conclusive since there are other oil pressure realted components, (tensioners).
If you decide to try this... let us know the results.
That's actually not a bad idea. But you would also need an oil pressure test gauge. That way you could observe any fluctuations in cam timing,,, up to the point the engine reaches 22 PSI... which is when oil pressure is restored to the cam phasers after leaking down. However this may not be 100% conclusive since there are other oil pressure realted components, (tensioners).
If you decide to try this... let us know the results.
04_Sport_LS
Dedicated LVC Member
OK,
Now you got me thinking about this. The LS 3.9 only "phases" the intake cam,,, so if your scanner can monitor the intake cam and exhaust cam simultaneously but separately... this may work. In theory... if the cam phaser is the issue,,, you would see fluctuations in timing only on the intake cam. But if a weak tensioner were the issue,,, you would see fluctuations on both cams.
Now you got me thinking about this. The LS 3.9 only "phases" the intake cam,,, so if your scanner can monitor the intake cam and exhaust cam simultaneously but separately... this may work. In theory... if the cam phaser is the issue,,, you would see fluctuations in timing only on the intake cam. But if a weak tensioner were the issue,,, you would see fluctuations on both cams.
Um, well, @#$% yes it helps. It helps massively. Huge thanks for your time and brain engagement. I don't think I need any more evidence than presented. The VVT unit leakdown seems completely in line with my symptoms. Particularly since it runs great, gets excellent mileage, passes smog etc. And by the way the old Gen two secondary chain tensioners looked A1 when I removed them and the new ones did not solve the problem. Further, when I pulled the cam cover there is no evidence of rubbing anywhere, the motor is clean as a safeway chicken and the (new) secondary chain is loose. All pointing to the vvt relaxing and leaving it loose.
who da man?
YOU da man!!!
Telco
Dedicated LVC Member
Sweet! That makes complete sense. I don't imagine a bleeddown problem is an issue to really worry about then. I might try the Castrol fix on my next oil change then, just changed the oil and am not interested in wasting good oil. With this next oil change I will be doing tomorrow I'll be running diesel engine oil, which runs fine in gasoline engines (used it before).
mpd4200
LVC Member
Great points on the intake vs exhaust cams. I wouldn't have thought of that or the oil pressure.
I can monitor oil pressure. But, it's what the computer thinks it is and may not be true.
I'll give it a go and see what I can capture.
I don't recall the exact cam timing I was measuring last weekend as there were a few available. But, it was fluctuating a few degrees every 10 seconds or so at an idle.
kevinspann
Active LVC Member
There are quite a few videos of Toyota VVT start up rattles which are exactly like what mine is doing. I pulled the valve covers and all the of the chains and tensioners look good.
The phasers require all of the timing chains to be removed since they gear is shared with the secondary timing chain. The issue is that the locking pin is no longer doing its job, so the phaser makes noise until oil pressure makes it there.
I'm trying to decide whether I want to do the job to replace them. It requires the timing tool set ($100 on ebay), 2 new phasers ($140 or so from Tasca) and 4 new bolts for the cam gears, and gaskets.
The phasers require all of the timing chains to be removed since they gear is shared with the secondary timing chain. The issue is that the locking pin is no longer doing its job, so the phaser makes noise until oil pressure makes it there.
I'm trying to decide whether I want to do the job to replace them. It requires the timing tool set ($100 on ebay), 2 new phasers ($140 or so from Tasca) and 4 new bolts for the cam gears, and gaskets.
04_Sport_LS
Dedicated LVC Member
Thanks for the kudos people,,, but I've been just as curious to solve this as everyone else. I did some more digging on the Jag forums... and there may be any easy fix.
http://www.jaguarforums.com/forum/s...vvt-issues-p1386-p1388-p1386-solenoid-112298/
Read post #3,,, and check the poster's sig. They have actually recommended this fix in multiple threads in the Jag forum.
http://www.jaguarforums.com/forum/s-type-s-type-r-supercharged-v8-x200-15/bad-vvt-68687/
If anyone is coming up on an oil change,,, try the 500 mile tranny fluid, (1 quart), swap.
http://www.jaguarforums.com/forum/s...vvt-issues-p1386-p1388-p1386-solenoid-112298/
Read post #3,,, and check the poster's sig. They have actually recommended this fix in multiple threads in the Jag forum.
http://www.jaguarforums.com/forum/s-type-s-type-r-supercharged-v8-x200-15/bad-vvt-68687/
If anyone is coming up on an oil change,,, try the 500 mile tranny fluid, (1 quart), swap.
mpd4200
LVC Member
I'll add a flush additive today. I have to draw a small oil sample for analysis first. I'm overdue for an oil change. I'll use the recommended oil type weight with one quart trans fluid for a month or so and then switch to rotella syn blend.
The scanner does show one cam timing measurement retarding timing until my rattle stops. I'll share this view ( I hope) now as I work towards a better view. I can only do the cold start rattle once per day as after the first start, it doesn't rattle again. Surprisingly I can't measure oil pressure with the scanner. I'll look for other useful info to tie to the cam timing.
The scanner does show one cam timing measurement retarding timing until my rattle stops. I'll share this view ( I hope) now as I work towards a better view. I can only do the cold start rattle once per day as after the first start, it doesn't rattle again. Surprisingly I can't measure oil pressure with the scanner. I'll look for other useful info to tie to the cam timing.
mpd4200
LVC Member
BTW, the timer on the bottom of the chart starts when I press "record" not when I turn on the key. I'll show another view with engine RPM as it's easy to see when I start the vehicle.
joegr
Dedicated LVC Member
Not really, sense there is no oil pressure sensor on the car. There's no way for the PCM to do anything but guess at the pressure. (The oil pressure switch just has two states. No pressure and enough pressure.)