1998 Gs300 Tappety Noise

[mattmanic]

Hello,

I've been doing some long over due maintenance on my recently purchased 1998 GS300 with 90k miles. I've drained and refilled the atf twice (still needs a couple more) changed the oil and filter, cleaned the vvti filter, I will be doing the differential oil on the weekend and taking it to lexus for a brake system flush soon :)

However! I noticed after the oil change the engine sounded much noisier at the top of the engine so I guess tappets? I used Mobil 5w30 fully synthetic and a bosch filter.

Do I need to be using a thicker oil as the car is quite old? Or do I need to get a genuine filter from Lexus?

Thanks :)

[ColinBarber]

If the filter was the problem then it would tend to only be noisy on startup and quickly go away.

I doubt the noise is causing a problem so only use thicker oil if you want to reduce the noise from an annoyance point of view. Fully synthetic oil tends to be thiner compared to mineral oil for the same protection rating and therefore can make the engine noisier. I've used Mobil 1 oil with many cars in the past and every one sounded worse when I started using it.

[mattmanic]

Thanks for the reply, so in all likelihood it's because the oil is thinner than the stuff it had in previously and nothing to worry about?

Googling brings up a few instances where people have recommended valve reshimming to account for wear. Do you know how necessary this is likely to be?

[ColinBarber]

It is extremely rare for a Toyota engine to need this done at the first 60k mile check. Given the age it is probably worth at least checking the clearance,

if any need adjusting then it is a pain because you need the proper tool and ideally a selection of shims to swap in and out, otherwise you need to check the clearances, remove the existing shims, measure them, put everything back together, calculate the different shim size, order the new shims, wait for them to arrive, strip down the vehicle again and hope the sizes are the correct ones.

[mattmanic]

Luckily my brother works at an engine refurbushers so I will check the clearances when I get some spare time. He has all the tools and shims I could need. Thanks for your help :)

[lexusmel]

I took my GS300 in for service and asked them to check what I thought was tappet rattle, turned out it is the fuel pump. If the noise is directly in front of you when sat in the drivers seat, then it is probably the pump, located at rear top of engine very close to bulkhead.

[mattmanic]

Well my brother had a listen and he said its fine and nothing to worry about, just me being pedantic :)

[lexusmel]

yes, me too, it's because the car is so quiet at idle, I can hear the ticking noise when the radio is off, when driving I can't hear it.