This 2006 GS300 only has 160,000 miles on it but It totally died on the highway, I restarted it once and drove it off the highway as it died again and never restarted. I had it towed to my local mechanic who said there is no engine compression and he pulled a plug and said the valve/s are not hardly moving. Then he said he does not like to do major engine work on a Lexus so I have to tow it to another garage now. I think it is a timing belt issue, what do you all think please?

 

The GS300 has a timing chain. So there are there no compression in any of the cylinder?

Since there are two codes relating to the camshaft sensor, I would check there first. Make sure that the the connector is secured.

 

That's correct, there is no compression whatsoever according to the mechanic.

 

I've seen this before, alternator went out. I bet if you read the freeze frame data you'll see low battery voltage.

If you tried cranking once it died, it's very easy to wash down the cylinders with mechanical pump. When you test it it'll show low compression.

Pull plugs, let dry, test alternator/ battery, only crank when voltage above 12v

 

Also, pulling a plug won't show you if valves are moving. Get a second opinion.

 

Thank you, will do.

 

check wire connector on cam sensor, they tend to back out. especially after replacing spark plugs. no compression possibly should of got misfire codes also

 

Thank you. Would that stop the engine from running and re-starting?

 

If the mechanic said theres no compression, I am assuming he ran a compression test through the spark plug hole. If theres no compression then something mechanical is bad. More likely cam/crank sensors will get triggered if the car doesnt start, but your car is not starting because the engine has no compression to fire on so the ecu thinks its the sensors that are bad.

I think you may have bad carbon buildup issue to where the point that the valves are stuck open. Therefore releasing the engines compression. I dont know how much mechanical experience you have, but you can see where the leaking is with a leak down test. Basically pressurize the spark plug holes with an air compressor and you listen to where it is hissing from. It could be from the bottom with a bad piston or a crack in the block, or from the top with a stuck valve, bent valve, bad valve seals, cracked head, bad valve spring, bad camshaft etc.

Another way to tell whats going on is to do a compression test, and test each spark plug hole. Verify which cylinder is losing the compression, that way you can remove the valve cover on the bad side, and with the valve cover off have someone crank over the engine and see what the valves and cams are doing. If you see something loose in between the cam and valve then thats your issue. You can also call the mechanic that did the compression test and ask him which cylinder was your engine losing compression at.

In the end, would take it to a mechanic that specializes lexus/toyotas who can do a cylinder head replace. More likely you will need to remove the heads or head and take it to a machine ship that will rebuild them with new valves seals/guides and clean them up aswell.

 

Agreed, no good mechanic would tell you that "the engine has no compression". They would tell you which/how many cylinders have no compression. The likelihood that all 6 cyl. are bad is just not realistic. Take it to someone else.

 

Thank you ibidu1 and tghw, your advice is much appreciated. I know have had three local mechanics say they don't want to work on it - that it is too major for them. That translates to "this is going to be expensive" as far as I am concerned. I found one mechanic that will work on it and he has a few master techs but none that are Lexus certified, he charges $140 / hr and the "Stealership" (dealership) only charges $149 / hr so I think I am going to take to the Stealership since the price difference is so little to get a certified Lexus tech working on it.

I will report back what was wrong and what the solution was in hopes it can help another member in the future. Thank you all for your sincere help and advice.

 

See how much the toyota dealer will charge, but I think youre better off finding a specialty shop. Also I wouldnt price things by the hour, I would rather price it by the job as a whole. That way you dont get nickle and dimed at the end.

 

Thank you and I agree completely.