Differences between VVTi & non-VVTi head? Got burnt valves (heavy pic content) - Toyota Nation Forum : Toyota Car and Truck Forums

Avalon 1st Generation (1995-1999) Specific discussion of the first generation Toyota Avalon

 4Likes
Reply
 
LinkBack Thread Tools Display Modes
post #1 of 33 Old 03-18-2017, 02:59 PM Thread Starter
Official TN Member
 
Join Date: Nov 2016
Posts: 51
Thanks: 9
Thanked 0 Times in 0 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 12 Post(s)
iTrader Score: 0 reviews
(Thread Starter)
Differences between VVTi & non-VVTi head? Got burnt valves (heavy pic content)

What are the differences between the two cylinder heads?

I am currently working on my 235k mile 1999 Avalon that has the non-vvti heads and apparently it appears this engine was poorly neglected or poorly maintained. I'm currently dealing with possibly a multitude of problems. A possibly blown head gasket and two burnt up exhaust valves for cylinder 2. It seems that at some point this engine has had either a coolant leak or signs of blown head gasket, and that I'm guessing the previous owner(s) or mechanic(s) tried to fix it by pouring/mixing in one of those Bars Stop Leak products in the coolant. There are traces of grey substances in the cooling system everywhere after partially disassembling the engine. There are also signs of ridiculous amount of RTV used for valve cover gaskets and lack of regular oil changes. This engine does leak oil, and now coolant is mixing in with oil.

Quick story about this car...

I bought this car back in November of last year and everything was running and driving fine till about a week ago when the engine lost power, was pulled over to the shoulder on the highway, and upon opening the hood, steam was coming out from both the driver and passenger side of the engine. The rubber sealing gasket in the radiator cap had deteriorated and lost cooling pressure and lost coolant as well. Car had to be towed back home. I read a couple of codes which few of it stated misfire in cylinder 2, an ignition circuit code (forgot the actual p-code), and a P0115 (coolant temperature circuit malfunction). Other codes were for emission control devices such as the EGR and Evap which has been there long before, and there was one transmission code.

I have confirmed there's spark (waste ignition spark system) and fuel in cylinder 2. I did a quick dry and a wet compression test and only got 30psi which tells me the piston rings are fine but there's definitely an issue with either the valves or the head gasket. My friend brought his air compressor and his leak down test over to help me out dig in with more troubleshooting. Because it was a windy day I couldn't properly hear air gushing out from the tailpipe, but the test did indicate severe air leakage in that cylinder. For the past few days, I tore down the engine to pull the bank 2 cylinder head out to discover and confirm my suspicions as shown in the pictures below.

I am now in need of another cylinder head and this is where I need some help in figuring out the differences between a vvti and a non-vvti head. Can I swap in a vvti head or is that impossible and won't work on my car?

Thanks

























Condition of the head gasket.







Cylinder 2







I see tiny holes in between cylinder 2 and 4.







This is the underside (facing towards the engine block) of the gasket between cyl 2 and 4.





Burnt exhaust valves cylinder 2.



auaq is offline  
Sponsored Links
Advertisement
 
post #2 of 33 Old 03-18-2017, 05:55 PM
BMR
Sheriff of Mayberry
 
BMR's Avatar
 
Join Date: Dec 2007
Location: Colorado
Posts: 9,034
Thanks: 347
Thanked 1,616 Times in 1,413 Posts
Mentioned: 17 Post(s)
Tagged: 0 Thread(s)
Quoted: 831 Post(s)
Lifetime Supreme Member
iTrader Score: 2 reviews
Can't answer your question about using a VVTi head.

Are the valve seats burnt too? If not, how about replacing the valves?

2015 RAV4 Limited, AWD, tech pkg, Barcelona red metallic, 31k miles
1996 Avalon XLS, ABS brakes, super white II, acquired w/ 139k, now at 352k
1992 Camry LE, V6 (3VZ-FE), ABS brakes, dark emerald pearl, owned since new. Replaced HGs @332k, totaled at 384k miles
BMR is offline  
post #3 of 33 Old 03-18-2017, 07:10 PM Thread Starter
Official TN Member
 
Join Date: Nov 2016
Posts: 51
Thanks: 9
Thanked 0 Times in 0 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 12 Post(s)
iTrader Score: 0 reviews
(Thread Starter)
I don't know yet, but I think whether burnt or not if I replace the valves I would also have to lap the valve seats.
auaq is offline  
Sponsored Links
Advertisement
 
post #4 of 33 Old 03-18-2017, 10:08 PM
Official TN Member
 
Join Date: Nov 2005
Location: Texas
Posts: 170
Thanks: 0
Thanked 8 Times in 7 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 10 Post(s)
iTrader Score: 0 reviews
On a car this old, (mine is also a 99 with 230k on it), I would seriously not think about retrofitting (relatively) newer powerplant parts. Since you have come this far, it would reaaaaally suck if you went through the trouble of installing a VVT-i head, then finding out that it won't work. Wouldn't the ECU need to be swapped out or reprogrammed for that too? I'll bet there's plenty of totalled 97-01 Avy's, Siennas, ES300's, Camry/Solara 6's out there with perfectly fine cylinder heads for the taking.
Why chance it?
Jagalag is offline  
post #5 of 33 Old 03-18-2017, 10:31 PM Thread Starter
Official TN Member
 
Join Date: Nov 2016
Posts: 51
Thanks: 9
Thanked 0 Times in 0 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 12 Post(s)
iTrader Score: 0 reviews
(Thread Starter)
True, I would have to change out the wiring harness and the ECU for a vvti conversion. I was merely curious to find out if the actual head casting is no different at all and that I could still retain/swap all the non-vvti parts in it and put this engine back together.

I'm actually thinking of partially rebuilding this head with two new exhaust valves, remove other valves and lap the valves and valve seats, install new stem seals if necessary, and also hot tank this head.
auaq is offline  
post #6 of 33 Old 03-19-2017, 03:23 AM
Official TN Member
 
Join Date: Nov 2005
Location: Texas
Posts: 170
Thanks: 0
Thanked 8 Times in 7 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 10 Post(s)
iTrader Score: 0 reviews
Quote:
Originally Posted by auaq View Post
I was merely curious to find out if the actual head casting is no different at all and that I could still retain/swap all the non-vvti parts in it and put this engine back together.

The main difference worth noting is that the Non-VVT-i heads are not prone to failure from bent valves if the timing belt suddenly snaps. Due to the non-linear operation of the VVT-i, it's more of a risk since the valve(s) might be in the open position longer. I'd say rebuilding the head you have is probably the best way to go, Getting a used head would be a distant second choice. I trust that you would go with an MLS headgasket for the repair? I hope you don't have to deal with cleaning all that sludge from the coolant and oil channels in the block. Looks nasty!

Last edited by Jagalag; 03-19-2017 at 03:26 AM.
Jagalag is offline  
post #7 of 33 Old 03-19-2017, 06:05 PM Thread Starter
Official TN Member
 
Join Date: Nov 2016
Posts: 51
Thanks: 9
Thanked 0 Times in 0 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 12 Post(s)
iTrader Score: 0 reviews
(Thread Starter)
Quote:
Originally Posted by Jagalag View Post
The main difference worth noting is that the Non-VVT-i heads are not prone to failure from bent valves if the timing belt suddenly snaps. Due to the non-linear operation of the VVT-i, it's more of a risk since the valve(s) might be in the open position longer. I'd say rebuilding the head you have is probably the best way to go, Getting a used head would be a distant second choice. I trust that you would go with an MLS headgasket for the repair? I hope you don't have to deal with cleaning all that sludge from the coolant and oil channels in the block. Looks nasty!
I've actually decided to rebuild the head. The plan is to obviously replace the burnt exhaust valves, remove all other intake and exhaust valves, clean them out, lap the valve's face along with the valve seats, while the head gets a thorough hot tank cleaning. Where can I order an MLS head gasket from? For the oil and coolant mix/sludge I'm going to drain all of that as much as I can and then I may pour in a bottle or two of ATF fluid along with regular oil for at least every 1000 miles or so in hoping for internal cleaning.

I didn't get to do much today since I don't have the right valve spring removal/compressor tool. I just ordered one off of eBay for about $18 + free shipping. The universal spring removal tool will never work on these heads because of its casting and how the buckets seat in there. In the meanwhile, I spent quite a considerable amount of time in cleaning the head and block's surface. Used a few razor blades to get most of the head gasket material out and then used a scotch brite to further clean the areas or spots that I couldn't remove with a blade. I did not wanted to do sand the surface down with too much pressure and in one constant area, as I wanted to retain some evenness across the entire head and on the block surface. I was trying to avoid any high and low spots if I was too aggressive while sanding. The surfaces feel smooth now and almost clean. Now I have to check for signs of warpage if it has any; however, I am inclined to think there might not be. I'm hoping all the oil galleries will get cleaned out.

Took few pictures today.









auaq is offline  
post #8 of 33 Old 03-19-2017, 07:10 PM Thread Starter
Official TN Member
 
Join Date: Nov 2016
Posts: 51
Thanks: 9
Thanked 0 Times in 0 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 12 Post(s)
iTrader Score: 0 reviews
(Thread Starter)
To flush the engine I might do this procedure:
  • Marvel Mystery Oil tossed in for 300 miles
  • LubroMoly Flush run for about 20-30 minutes or so
  • Penzoil 5W20 conventional with new filter for 3000 miles
  • Then try Rotella T5 10W30 for every 3000 miles
It will be interesting to see how this works out.
auaq is offline  
post #9 of 33 Old 03-19-2017, 07:13 PM
Official TN Member
 
Join Date: Nov 2005
Location: Texas
Posts: 170
Thanks: 0
Thanked 8 Times in 7 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 10 Post(s)
iTrader Score: 0 reviews
Make sure you know the month and year of production date before ordering a gasket kit. They did some minor engine revisions in that production year beginning on August 1st 1999. It could mean different specs in the gasket print. Heads should be resurfaced by a professional shop to within tolerances. Both block and Head surfaces checked for warping using a mechanics straightedge ruler and feeler gauge.
auaq likes this.

Last edited by Jagalag; 03-19-2017 at 07:19 PM.
Jagalag is offline  
The Following User Says Thank You to Jagalag For This Useful Post:
auaq (03-19-2017)
post #10 of 33 Old 03-19-2017, 07:17 PM Thread Starter
Official TN Member
 
Join Date: Nov 2016
Posts: 51
Thanks: 9
Thanked 0 Times in 0 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 12 Post(s)
iTrader Score: 0 reviews
(Thread Starter)
Quote:
Originally Posted by Jagalag View Post
Make sure you know the month and year of production date before ordering a gasket kit. They did some minor engine revisions in that production year beginning on August 1st 1999. It could mean different specs in the gasket print. Heads should be resurfaced by a professional shop to within tolerances, and the block surface checked for warpage using a mechanics straightedge ruler.
Thanks for the heads up. Will check on the right p/n.

I've already ordered a straight edge and will check the tolerances. If found beyond specs, then I'll have the head resurfaced.
auaq is offline  
post #11 of 33 Old 03-19-2017, 07:42 PM
BMR
Sheriff of Mayberry
 
BMR's Avatar
 
Join Date: Dec 2007
Location: Colorado
Posts: 9,034
Thanks: 347
Thanked 1,616 Times in 1,413 Posts
Mentioned: 17 Post(s)
Tagged: 0 Thread(s)
Quoted: 831 Post(s)
Lifetime Supreme Member
iTrader Score: 2 reviews
Rockauto.com offers both MLS and composite head gaskets. Be aware that MLS gaskets are fussier about surface prep, needing a finer surface finish than composite. If it were mine I'd go composite unless both heads and block surfaces were professionally resurfaced.

2015 RAV4 Limited, AWD, tech pkg, Barcelona red metallic, 31k miles
1996 Avalon XLS, ABS brakes, super white II, acquired w/ 139k, now at 352k
1992 Camry LE, V6 (3VZ-FE), ABS brakes, dark emerald pearl, owned since new. Replaced HGs @332k, totaled at 384k miles
BMR is offline  
post #12 of 33 Old 03-20-2017, 01:50 PM Thread Starter
Official TN Member
 
Join Date: Nov 2016
Posts: 51
Thanks: 9
Thanked 0 Times in 0 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 12 Post(s)
iTrader Score: 0 reviews
(Thread Starter)
Quote:
Originally Posted by BMR View Post
Rockauto.com offers both MLS and composite head gaskets. Be aware that MLS gaskets are fussier about surface prep, needing a finer surface finish than composite. If it were mine I'd go composite unless both heads and block surfaces were professionally resurfaced.
With the surface finish I think I'm just going to stick with the OEM gasket.
auaq is offline  
post #13 of 33 Old 03-21-2017, 12:49 AM
Official TN Member
 
Join Date: Nov 2005
Location: Texas
Posts: 170
Thanks: 0
Thanked 8 Times in 7 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 10 Post(s)
iTrader Score: 0 reviews
just don't forget to replace the Header gaskets, intake runner gaskets, spark plug tube seals.... etc. These cars are notorious for valve cover leaks also, so be very careful about which VC gaskets you pick. IMO, Fel-pro makes a solid product in that department. EndZone wrote a pretty detailed tutorial on the 2nd gen forum.
auaq likes this.
Jagalag is offline  
The Following User Says Thank You to Jagalag For This Useful Post:
auaq (03-21-2017)
post #14 of 33 Old 03-21-2017, 09:26 AM
New TN User
 
Join Date: Jan 2017
Location: Sundance Mesa, NM
Posts: 28
Thanks: 0
Thanked 1 Time in 1 Post
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 8 Post(s)
iTrader Score: 0 reviews
Hey auaq, was finally able to sign in on my PC. Not sure why I couldn't on the iPad.
Looks like you have a lot of clean up to do.
Just drop an LS in it and be done with it, lol. Knew that would get you steaming...
Good Luck.
auaq likes this.
JimLev is offline  
The Following User Says Thank You to JimLev For This Useful Post:
auaq (03-21-2017)
post #15 of 33 Old 03-21-2017, 01:03 PM Thread Starter
Official TN Member
 
Join Date: Nov 2016
Posts: 51
Thanks: 9
Thanked 0 Times in 0 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 12 Post(s)
iTrader Score: 0 reviews
(Thread Starter)
Quote:
Originally Posted by Jagalag View Post
just don't forget to replace the Header gaskets, intake runner gaskets, spark plug tube seals.... etc. These cars are notorious for valve cover leaks also, so be very careful about which VC gaskets you pick. IMO, Fel-pro makes a solid product in that department. EndZone wrote a pretty detailed tutorial on the 2nd gen forum.
Yep, have a list of items that I will be changing namely: vcg, pcv valve, cam seals and may change the crank seal, head gasket, need Toyota coolant, upper + lower intake gasket, and I need to change the upper engine mount.
auaq is offline  
Sponsored Links
Advertisement
 
Reply

  Toyota Nation Forum : Toyota Car and Truck Forums > Toyota Passenger and Sports Car Forums > Avalon Forum > Avalon 1st Generation (1995-1999)

Bookmarks

User Tag List

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome
Back