Project from Hell

2009 AWD IS250 driven by my daughter.

Developed a leak in the radiator side tank seal.

Ok no big deal, Change the radiator fill coolant and send her on her way. Couple weeks later the AC compressor grenades and locks up. Ok new compressor and condenser with filter bag because the crap from the compressor is probably trapped in it. Send her on her way. Another couple weeks, the heater doesn’t blow hot and the temp gauge is at cold. We know that means there’s no coolant. She tries to get off the interstate but it looses power and won’t go any farther. I come with lots of water and get it home after numerous stops to top of radiator and overflow tank. Seems the head gasket has a breach on the #4 cylinder putting compression into the cooling system blowing all the water out the overflow tank most likely from the original loss of coolant by the tank leak. Cool, confirmed by a #4 misfire code if I leave it sit pressurized over night. It was pushing coolant into the cylinder and causing the misfire. I actually drove it a couple months with a lever releasing coolant cap that I bled off the pressure when parked to avoid the misfire code.

I have a friend that works at the local Lexus dealership and asked about changing the head gaskets. He said yeah you don’t want to do that at home. The quote was $4K and up depending on what else was bad. I decided I could do it at home, how hard can it be right? Allow me to tell you how freaking hard it is.

1. The heads don’t just come off. The timing cover has to come off before the heads.
2. The timing cover is pinned into the oil pan which requires the engine to come out to get the oil pan off.
3. The engine is supposed to come out the bottom with the entire sub frame and steering components as a unit requiring a hoist.
4. My buddy said it isn’t worth trying to pull it from the top. Well it’s got 130K on it, I paid $7K 3 years ago and it’s worth zero as it sits.
5. I’m a dumbass so here we go, to get it out through the top, the entire front end has to come off along with disconnecting all the suspension and front drive axles. Because oh yeah, the right front CV goes through the freaking oil pan via a tube in the pan to the front differential on the left side of the engine. Anyone that has had to pull the right CV carrier bearing from the oil pan housing knows what a pain that is. (Torch and slide hammer).
6. It’s out with the tranny, as the tail swings into the 1 year old condenser and punched a hole in it, sorry ozone. Now on the stand and tear into this thing.
7. With double over head cams and tensioners the cam chain is like 12 feet long. Again thanks to my pal at Lexus, don’t trust the marks on the cams, crank and chain because they didn’t pay attention to those at assembly. I marked everything where it was as it came apart and sure enough the links and marks were off a tooth or two.
8. The head on the drivers side had the breached gasket and was warped .008 so I milled that and reassembled the engine and put it back in hoping the chain was right.
9. While it was sitting for the 6 weeks I was working on and off this project the rotors rusted and it turns out if you leave it sit out of fuel, the electric pump in the tank will soon fail. Turned the rotors, replaced the fuel pump and we’re onto putting some miles on to **** out the kinks.
10. 50 miles in I get the P0156 and P0158 running too rich codes and the pressure line from the the tank pump all the way to the inlet of the engine driven high pressure pump is pulsating and vibrating like an out of balance heater fan.

This is where I’m at currently. I’m thinking some crap from the milling got into or under an injector because I left the rail intact when we milled the head and it is not closing causing the regulator (snubber) to pulsate and fuel to drool into a cylinder causing the rich engine code.

This thing is possessed but I’m almost there.

Let me know if you’ve seen this pulsating fuel line because I really don’t want to take the entire intake off again to swap injectors.

See the pics, sorry for the random order.

So far I’m probably into it for $600 with the machine work and parts. My labor is free.

Lex



Castrol synthetic every 5K. Very clean.



This side was one tooth off from the factory.

Note lower subframe with sterling and suspension on bottom of hoist.

 

I don't like the sound of that, leaving the fuel rain on place when the head was machined. There is a whole lot of particles flying around sure the head is washed after but still. You're a brave man to take on this project there are so many steps and potential for things to go wrong.

Hope you get the fuel thing sorted, I'll think about it but right now can't come up with why it is happening

 

Thanks LeX2K, I have a laptop with Techstream and hope to see what the fuel pressure is doing.
These don’t have an actual pressure regulator but a snubber/ absorber that is supposed to take out the pulses.
i saw another thread here about the same pressure line pulsating but no resolution was given.

Lex

 

I'm looking at P0156/P0158 and see secondary O2 sensor malfunction. As in, most everything points to a wiring and/or sensor fault. Due to the work done, it seems more likely that a common wire between the two has been compromised or fuse blown. Did you drop the mid-pipe? What makes you think the pulsation is an issue or something new?

Unfortunate about the condenser. That sucks.

As for the timing chains being off, it's nearly impossible to get both banks to align at the same after its been ran. If links were counted down to the crank, it was off the same amount you found up top or it would never have run right. Think in terms of a one time reference point. I wouldn't worry about it if all ligned up correctly during assembly. I'm guessing you had to spin it lot to get the one bank to line up as it did.

 

Yeah I had the whole exhaust off. The sensors might be trashed from the coolant or the seafoam I ran at a richer than normal amount. The pulsing/vibration of the fuel line from the tank to engine driven pump is new. I have about 50 miles on it since putting it together and the noise just started. I swapped the regulator/absorber with my ‘07 IS350 but it was the same.
I have a new electric fuel pump coming under warranty to see what it does.
I’d really like to see a schematic of the fuel system to see if there is a check valve or something causing the pulsation.
Attached is a shot of the techstream data after warmed up. Yes the pressure to the injectors is 600psi and can go as high as 1500psi.

Thanks for the reply,
Lex

 

My 350 runs from 1700 to 2600. Most of the time it's 1900 to 2100 psi.

 

Hooray! I think I got it!
I put warranty electric fuel pump in today, easiest pump install ever by the way.
Noticed when I pulled the lines off there was no fuel or pressure. Even the original failed one that would run a few seconds sprayed fuel when disconnecting the output line.
My guess is there is a check valve in the pump assembly that wasn’t sealing causing the pulsing/vibration.
I cleaned the MAF sensor and have about 25 miles with 6 or 7 starts and have no pump noise or even any pending codes!
Fingers crossed I can turn it loose for now.
Lex

 

congrats dude!