Advice on failed LS 400, which has now stopped.

michael Vercell · March 1, 2023

I have owned this car from new., full service history, from Lexus initially,now my local garage. The car stopped two days ago and investigation suggests a broken cam shaft with no compression in the engine. The car is immaculate all functions work, leather upholstery is perfect, the car was fitted from new with the dynamic handling package with the larger alloy wheels and tires. My question has anyone any experience of swapping the old engine for a replacement engine ? Is this a viable option ? As I said i have had this car from new and hold an emotional attachment to her.

The-Acre · March 1, 2023

1 hour ago, michael Vercell said:

I have owned this car from new., full service history, from Lexus initially,now my local garage. The car stopped two days ago and investigation suggests a broken cam shaft with no compression in the engine. The car is immaculate all functions work, leather upholstery is perfect, the car was fitted from new with the dynamic handling package with the larger alloy wheels and tires. My question has anyone any experience of swapping the old engine for a replacement engine ? Is this a viable option ? As I said i have had this car from new and hold an emotional attachment to her.

I've never heard of that before in the LS400 engine. I don't see why a replacement engine wouldn't be the way to go, it's just a matter of sourcing one. Would your local do the work for you?

Tinonline · March 1, 2023

28 minutes ago, The-Acre said:

I've never heard of that before in the LS400 engine. I don't see why a replacement engine wouldn't be the way to go, it's just a matter of sourcing one. Would your local do the work for you?

Sounds more like a snapped cam belt…

Should be a few units around with ok mileage…the bodywork/ chassis took most to an untimely end.

steve2006 · March 1, 2023

When was the cam belt last replaced?
The earlier models up to October 1994 had non interference engines but later models with higher compression ratios became interference.

At one time engines could be got for £500.00 or so but with less survivors now finding a good one for less than £1K could be a challenge.

The-Acre · March 1, 2023

9 minutes ago, Tinonline said:

Sounds more like a snapped cam belt…

Should be a few units around with ok mileage…the bodywork/ chassis took most to an untimely end.

That's what I first thought, the cam belt. I suppose it depends on how much investigation was actually carried out or whether it's just an assumption.

ambermarine · March 1, 2023

Changing the engine is a major task and after a replacement is fitted marrying up the security and ecm needs software updates so it could be costly and its unlikely Lexus dealerships would take the task on.This then leaves you in the hands of a independant who may not have the back up to get it running after installation.

I would get an analysis of what as occured in your present engine because an insitu rebuild of that may be more within the capabilities of an independant,and there would be no issues marrying it up to your present security and transmission.

Spock66 · March 1, 2023

Plus a second hand engine will be an unknown quantity with a very limited warranty.

Scribe · March 1, 2023

Would be interested in having more details, if you're willing to share them, e.g. what's the car's mileage and when was the cambelt last changed (date and mileage)? My (indy) mechanic says that whenever he's changed a belt on an LS400 the old one has never shown any signs of wear - not that that's a reason to put off the replacement. Mine's due next year, I think, after 10 years but only about 25,000 miles.

Phil's (ambermarine) suggestion sounds sensible, given that you'd have to source a decent engine - and how would you know it's okay? I gather most of them find their way straight into other cars. I met someone the other day who put one in a Toyota Hi-Lux pickup.

Supafly · March 1, 2023

I've changed a few engines in my time and it is definitely a doable job. It requires focus and meticulousness.

I've never changed a 1uz, but the principles are the same. I don't think that there will be any issues with security, engine control module or transmission if replacing like for like. There aren't any 'smart' components on these engines that 'communicate with the ecu, only sensors that feedback a defined value based on operating conditions. So it is literally plug and play. This is one area that there may be issues with clips breaking etc but this is par for the course dealing with older cars and can be resolved by replacing the connectors/sensors if needs be.

There may be tiny differences in fuel injector flows etc, but the ecu can adapt based on sensor readings and time driving the car.

I agree with ambermarine:

"I would get an analysis of what as occured in your present engine because an insitu rebuild of that may be more within the capabilities of an independant,"

However it's usually cheaper to replace the engine than to rebuild one in situ as all the components quickly add up...

for example if the belt snapped and pistons said hello to valves:

Replace broken connectors

Gasket sets

Replacement valves

Valve stem seals

timing belt, water pump, pulleys and tensioners, valve adjustment

Replacement pistons if badly damaged, ring set, potentially bearings etc

If you're paying a garage to do this then it really starts to add up.

If you were to replace the engine like for like it would make sense to do the timing belt etc if condition was unknown and then any connectors/sensors that are damaged.

Apologies if I rambled a bit(replying quickly while at work), happy to clarify any points if you need

Malc1 · March 1, 2023

Michael, so sorry to hear of this disaster with your beloved Ls400

Echo all the above really .......... what mileage has she done and when was the cambelt last changed and at what mileage ? did the garage place an appropriate sticker on the engine somewhere ?

NOW .... . is she a Mk3 or a Mk4 car ? ....... and can you share the reg no. ? We are all so inquisitive on here you know 😅

Best wishes

Malc

michael Vercell · March 2, 2023

22 hours ago, The-Acre said:

I've never heard of that before in the LS400 engine. I don't see why a replacement engine wouldn't be the way to go, it's just a matter of sourcing one. Would your local do the work for you?

That’s one of the problems my garage is not keen to take on this work.

Razor61 · March 2, 2023

What a shame, sorry to hear about it.
I have no experience of replacing the engine in a LS400 or having one replaced and I don’t think there will be many people that do have experience to be honest.
Having said that, if I was in your situation I would have a go at removing the engine myself. Initially not a great deal to lose removing the engine, a few quid for an engine hoist, time, effort and probably a lot of frustration etc. Then decide what to do. Purchase a used engine, check it over and if it’s ok then fit it to the car or rebuild the existing engine if possible. I do most of the work on my LS400 myself so easy for me to say and I’ve removed engines and rebuilt them in the past so I wouldn’t be fazed by giving it a go.
Most garages won’t want to get involved, it’s a big car to be sat in the workshop taking up space, big lump of an engine to remove and something they have no experience of rebuilding or even looking at. And there is the cost for a garage to do the job.

Malc1 · March 2, 2023

Paul ..... I'm thinking Merseyside isn't too far from you . there's a job coming on maybe ? give it a go ?

......... and Michael . do you have any answers to my points above perhaps ?

Malc

ambermarine · March 2, 2023

This is a job for a well experienced pro and not an amatuer project unless you do not care about the end of the road outcome.Personally If it as serious internal damage I would cut my losses and break it for the parts they are very sought after in good condition and getting rare although there are still good examples around so parts will be needed in the future.

I can see from your post that you are very attached, so why not buy a like model and swap some of the touchy feely things like seats and steering wheel from yours to an acquisition that way you get to experience your old car in a new one.

Razor61 · March 2, 2023

59 minutes ago, Malc1 said:

Paul ..... I'm thinking Merseyside isn't too far from you . there's a job coming on maybe ? give it a go ?

......... and Michael . do you have any answers to my points above perhaps ?

Malc

I’d have a go if it was my car and the condition of the car made it worthwhile. I’m not an ‘experienced pro’ in the mechanic sense but I’d back myself to get the engine out and fit a replacement. I’d also back myself to rebuild a 1uz engine if needed, rebuilt other engines in the past. Granted not as complicated or as big as the 1uz but the same principles apply and I have the workshop manual, experienced engineers/mechanics to call upon if needed.

Tinonline · March 2, 2023

Hang on…best to have a definitive determination on the cause and damage. Garages like easy work and fast turnover.

Maybe they’d like to buy the car and fix it.

A home mechanic could do the work but it’s a labour of love and may take time and money. Less money if good at buying.

I don’t see any answers to our questions posed.

The-Acre · March 2, 2023

Just a thought. Is Paul Frost still going? As a Lexus breaker and repairer, I'm guessing he's only about 50 miles from Merseyside. Surely it's a job he would undertake.

Tinonline · March 3, 2023

Well the poster joins Wednesday and posts…smacks a bit of trader bought a dud?

Trade always says car won’t start which equals was broken when they bought it…and you don’t miss a belt or related break…there’s a big instance.

So my advice if this is the case is to sell “her” for spares. It sounds like the later Lexus from the updates referenced.

It would have to be low mileage for engine work.

Malc1 · March 5, 2023

On 3/3/2023 at 8:36 PM, Tinonline said:

smacks a bit of trader bought a dud?

Well well well .. could it be that weird wheeled wonder on Autoafraider a few weeks back that was mentioned here before somewhere .... the one i sent off for some detail from the seller / garage and they popped the price up and never did respond to me . most contributors here thought it was a " no no "

It vanished soon after that ....... wonder if it's that car / trader caught a cold with it

Malc

rich1068 · March 5, 2023

Why the conspiracy theories?

What indication is there that the OP is a trader that bought a dud? Absolutely none.

Not everyone joins owners forums, quite often people who join don't come back after posting once or twice, not everyone who's bought a Lexus posts here and more importantly not every owner knows the ins and outs of engine maintenance.

This isn't the first time this has happened. It's bizarre.

Tinonline · March 5, 2023

7 hours ago, rich1068 said:

Why the conspiracy theories?

What indication is there that the OP is a trader that bought a dud? Absolutely none.

Not everyone joins owners forums, quite often people who join don't come back after posting once or twice, not everyone who's bought a Lexus posts here and more importantly not every owner knows the ins and outs of engine maintenance.

This isn't the first time this has happened. It's bizarre.

Very ready to eat my words. As Malc alludes we have a number of doesn’t stack posts from trade…we’ve seen quite a few and this ticks boxes…the language is a ringer…let’s wait for specific vehicle details and a dialogue. Don’t hold your breath. 🫣😁