Rattling Noise From inside the Engine Compartment .

[Ian R.]

Hello All,

The van only makes the noise while under power going up steep hills, when it is bogging down. The rattle is constant and goes away after getting over the incline. It happens in all gears, but in the similar situation described above.

It does not make the noise when revving the motor in neutral. There is a tapping sound at start up the goes away when warm. Could it be a lifter?

Anther weird thing is that the E-brake light comes on when shifting at higher RPMs:dizzy:

[timsrv]

Check your motor mounts. It's very common for the one on the driver's side (under the exhaust manifold) to break. This could allow the engine to lift and/or move around while under acceleration.

Tapping sound when cold could very well be a lifter.

The brake fluid reservoir has a float in it. When the level gets low it turns on the brake light in your instrument cluster. If the fluid level is marginal, it's common to see the light flicker and/or come on for a second or two while going around a sharp corner or making other sudden movements (like shifting gears under acceleration). Tim

[tjbrain]

Hello to the original poster (and all others!), I have a 1986 Toyota van, 4x4, EFI with 4y Engine and 5 speed trans, and I'm having the exact same symptoms as original poster. Some clatter/rattle under load (ie. going up a hill in 4th or 5th).

Was this ever resolved?

Here's why I find it especially puzzling - it's a similar rattle to the pinging you hear when an engine is too advanced. And, considering it only happens when lugging down, that could be the problem. Do 4y engines have a history of pinging or are sensitive to running too advanced? Is the vacuum advance actuator on the distributor known for going bad on these?

But! I only get the rattle once the engine has warmed up. For the first 5 - 10 minutes of driving (assuming I haven't warmed up too long under idle) I cannot replicate it no matter what I do. I have a nice, fairly steep little hill about a mile away, and if the van is warm - clatter. If the van is cold, in the morning, first run of the day - no clatter, even floored in 4th, bogging at 1500 rpm. The only other time I have had noticeable pinging on a car was a 67 Nova with an inline 6, and I had it too advanced after a new distributor install. It would clatter cold, hot - didn't matter.

The van has 208k miles, so maybe carbon deposits in the combustion chamber heat up and cause pinging? I'm just spitballing.

Or maybe it's just the motor mount (I'll check in the morning).

Thanks guys. Oh - and I'm in Costa Rica. So throwing parts at it is not a good or easy or cheap option.

[llamavan]

I recently cured a rattle (and "pinging"!) when I spotted and removed a broken bolt that had found its way to the top of the intake manifold. It was apparently dancing around whenever the engine was running. Obviously the intake manifold makes a good resonance chamber.

FWIW, YMMV ...

Gwen

[CargoPanel111]

I have also noticed a problem with what appears to be pinging with my 1988 Cargo van. I retarded the timing a couple of degrees a while back and that seemed to take care of it, but recently the problem re-appeared intermittently. I also noticed the timing did bounce around a little on the timing light. The van has low orig miles, but wondering if the timing chain or a related component may need replacement. THANKS VERY MUCH for any insights/info. -john

[timsrv]

Hi John,

I noticed in your profile your van only has 140k miles on it. If that's still accurate, then I wouldn't immediately assume the timing chain to be the issue. I suppose it's possible, but these timing chains typically run beyond 250k before becoming an issue. For pinging, aside from ignition timing I think the TPS (Throttle Position Sensor) would be a much more likely cause.

1st off, check your timing with a jumper in your "Check Engine Connector" (https://www.toyotavantech.com/forum/content.php?196-Engine-Service-Connector), then pull the jumper and check it again. If your electronic advance is working the timing will change significantly after pulling the jumper. If there is no change, then you should concentrate your efforts on troubleshooting the electronic advance system. Checking engine codes (also in that link) may also offer some clues. It's been my experience that 90% or more electronic advance problems are due to a failed TPS (codes 7,8 or 11).

FYI, timing should be set/checked with a jumper installed in the check engine connector. If you set the timing without the jumper installed, then your timing would be way off. Tim

PS: For other users reading this, the electronic advance is used on 86 - 89 vans only. If your van is an 84 or 85 you will have vacuum advance. Vacuum advance is checked by removing and plugging the vacuum line from the distributor while setting/checking timing. After timing is set vacuum line is hooked back to the distributor and timing is checked again. If it's working there should be a significant change in the timing. If not, use a MitiVac to pull a vacuum on the distributor diaphragm (in the old days we used to use our mouths and an extra piece of vacuum hose). If a vacuum cannot be achieved or if it can't hold a constant vacuum, then that diaphragm will need to be replaced. Codes are checked the same way for all years. Follow the link above to see the codes for your year of van.

[CargoPanel111]

Thank you Tim for your kind and very helpful information. i will proceed as you have advised. The Van has been a blessing to have and i need to show it the needed attention. i will let you know how it goes. Highest regards. -john

[CargoPanel111]

Thinking i may have a bad Cat(the van still had the original), i recently replaced it with a new Magnaflow. I only used my van for very short trips for the last three weeks until yesterday when i took it out on the Highway for a 80 mile round trip jaunt that took me over some hills. No pinging on the way out, but it re-appeared a little on the way back. Also, i got two codes 25 and 26. In the past i would get a flickering CEL, but could not read any codes. It was good to finally get the codes, but now what to do??? Has anyone had these codes? Thanks much for any information.

[timsrv]

I'm a bit confused because there is no code 25 or 26 on 86 vans. Are we talking about the same van listed in your profile? If so, then somebody may have installed the wrong ECU in your van. If your van is an 88 or an 89, then those codes indicate a lean running condition and a rich running condition (they conflict). Usually that means bad O2 sensor(s). Keep in mind there are (2) O2 sensors on 88 & 89 vans, but only one on an 86, so the newer ECU won't function correctly if it's installed on an 86 (unless you also update the sensors).

Next thing to do is to check your door tag for the manufacture date, then pull the the DS seat belt panel (by your left shoulder) and check the number on your ECU. I'd also take a peek underneath to see if there's an O2 sensor behind the cat. Let me know what your find. Tim

[CargoPanel111]

Tim, Thank you so much for your reply. You are right, i have two vans and i forgot to add the 1988 to my profile. This is the 1988 with the codes 25 and 26. It does have two oxygen sensors. Not sure how to test their operation, but perhaps i can find this online or hopefully in the manual. It would be awesome to finally solve the problem. Many, many thanks for all your help. -john

[timsrv]

It's worth saying that in order to figure things out it helps to know what we're are working on :yes:. Not such a big deal for general things but EFI/Emission problems it's particularly important as to help avoid confusion (several major changes made throughout the years).

Personally I consider O2 sensors to be routine maintenance items (sort of like spark plugs). If I had a problem like yours and I didn't know how old the sensors were, I'd just change them.......especially if the van has over 100k miles. There is however a test procedure in the manual so I copied and pasted below:

http://i8.photobucket.com/albums/a23/timsrv/TVT%20pics/emissions/88-89%20O2%20Sensor%20Testing_zpsbssafbuq.jpg

If/when you're ready to change sensors, here's a thread that should help identify/order the correct ones.

https://www.toyotavantech.com/forum/showthread.php?415-Oxygen-sensors-part-numbers-(all-years)-and-replacement

If they test good, or if replacing them doesn't fix problem, then I'd recommend purchasing a service manual for your year van and checking/testing the other components in the EFI system. Tim

[CargoPanel111]

Thank you Tim for the great info. Since i don't know how old the sensors are, it makes sense to get new replacements. Thankfully i have a back-up vehicle and can just park the 1988 until the new sensors are in. Thank you for helping us all keep the great Toyota Wonder Wagons on the road. I still love it when i see another one on the road, unfortunately that is becoming more and more of a rarity. Highest regards... -john